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**Jonesie** · December 31, 2006, 11:27 AM

Re: PREVENTING INDOOR HYPOTHERMIA

AND FOR THOSE WHO DESIRE MORE READING MATERIAL REGARDING HYPOTHERMIA, HERE ARE SOME LINKS:

HOME TREATMENT:

http://www.medicalhometreatment.com/hypothermia.htm

Diagnosis and Treatment of Hypothermia:

Page Not Found | AAFP

http://www.aafp.org/afp/20041215/2325.html

http://www.theberries.ns.ca/archives/Hypothermia2.html

http://www.blackwell-synergy.com/links/doi/10.1046/j.1525-1489.2001.00142.x

CDC:
And if someone knows how to post charts (I don't) the CDC has several good charts on their Hypothermia info pages:

http://www.bt.cdc.gov/disasters/winter/guide.asp

http://www.bt.cdc.gov/disasters/winter/faq.asp

Hypothermia-Related Deaths --- United States, 1999--2002 and 2005

http://www.cdc.gov/MMWR/preview/mmwrhtml/mm5510a5.htm

U OF M:

404 Not Found

http://www.med.umich.edu/opm/newspage/2006/hmheating.htm

AMERICAN HEART ASSOCIATION:

American Heart Association | To be a relentless force for a world of longer, healthier lives

http://www.americanheart.org/presenter.jhtml?identifier=3027990

Learn more about the American Heart Association's efforts to reduce death caused by heart disease and stroke. Also learn about cardiovascular conditions, ECC and CPR, donating, heart disease information for healthcare professionals, caregivers, and educators and healthy living.

**Sally Furniss** · December 31, 2006, 07:34 PM

Re: PREVENTING INDOOR HYPOTHERMIA

<h1 align="center" class="BOLD">Outdoor Action Guide to 

Hypothermia And Cold Weather Injuries</h1>

<h3 align="center">by Rick Curtis</h3>

<table border="1" width="100%" bgcolor="#FFFF99">
<tr>
<td width="100%"> Traveling in cold weather conditions can be life threatening.
The information provided here is designed for educational use only and is not a substitute for specific training or experience. Princeton University and the author assume no liability for any individual's use of or reliance upon any material contained or referenced herein. Medical research on hypothermia and cold injuries is always changing knowledge and treatment. When going into cold conditions it is your responsibility to learn the latest information. The material contained in this workshop may not be the most current.</td>
</tr>
</table>

<h2>How We Lose Heat to the Environment</h2>



How we lose heat


<ol>
<li>Radiation - loss of heat to the environment due to the temperature gradient (this occurs only as long as the ambient temperature is below 98.6). Factors important in radiant heat loss are the surface area and the temperature gradient. </li>
<li>Conduction - through direct contact between objects, molecular transference of heat energy <ul>

<li>Water conducts heat away from the body 25 times faster than air because it has a greater density (therefore a greater heat capacity).
Stay dry = stay alive! </li>
<li>Steel conducts heat away faster than water </li>
</ul>
Example: Generally conductive heat loss accounts for only about 2% of overall loss. However, with wet clothes the loss is increased 5x. 
</li>
<li>Convection - is a process of conduction where one of the objects is in motion. Molecules against the surface are heated, move away, and are replaced by new molecules which are also heated. The rate of convective heat loss depends on the density of the moving substance (water convection occurs more quickly than air convection) and the velocity of the moving substance. <ul>

<li>Wind Chill - is an example of the effects of air convection, the wind chill table gives a reading of the amount of heat lost to the environment relative to a still air temperature. </li>
</ul>
</li>
<li>Evaporation - heat loss from converting water from a liquid to a gas <ul>
<li>Perspiration - evaporation of water to remove excess heat <ul>
<li>Sweating - body response to remove excess heat </li>

<li>Insensible Perspiration - body sweats to maintain humidity level of 70% next to skin - particularly in a cold, dry environment you can lose a great deal of moisture this way </li>
<li>Respiration - air is heated as it enters the lungs and is exhaled with an extremely high moisture content </li>
<li>It is important to recognize the strong connection between fluid levels, fluid loss, and heat loss. As body moisture is lost through the various evaporative processes the overall circulating volume is reduced which can lead to dehydration. This decrease in fluid level makes the body more susceptible to hypothermia and other cold injuries. </li></ul></li></ul></li></ol>
<h2>Response to Cold</h2>

Cold Challenge - (negative factors)
<ul>
<li>Temperature </li>
<li>Wet (rain, sweat, water) </li>

<li>Wind (blowing, moving, e.g. biking) 
Total = Cold Challenge </li>
</ul>

Heat Retention - (positive factors)
<ul>
<li>Size/shape (Eskimo vs. Masai) </li>
<li>Insulation (layering/type) </li>

<li>Fat (as insulation) </li>
<li>Shell/core (shunt blood to core) shell acts as a thermal barrier 
Total = Heat Retention </li>
</ul>

Heat Production - (positive factors)
<ul>
<li>Exercise, shivering Limited by: <ul>
<li>Fitness </li>
<li>Fuel stores (glycogen) </li>
<li>Fluid status (efficient exercise) </li>
<li>Food intake (kindling, sticks, logs) </li></ul>
Total = Heat Production </li></ul>
<table border="1" cellpadding="5" bgcolor="#00FFFF">
<tr>
<th>Heat Retention</th>
<th>+</th>
<th>Heat Production</th>
<th>less than</th>
<th>Cold Challenge</th>
<th>=</th>
<th>Hypothermia</th>
</tr>
<tr>
<td>Insulation 
Body Fat 
Surface to Volume ratio 
Shell to Core shunting</td>
<td> </td>
<td>Exercise 
Shivering</td>
<td> </td>
<td>Temperature 
Wetness 
Wind</td>
<td> </td>
<td> </td>
</tr>
</table>

<h2>Your Body Core Temperature</h2>

1. Heat is both required and produced at the cellular level. The environment acts as either a heating or a cooling force on the body. The body must be able to generate heat, retain heat, and discharge heat depending on the body activity and ambient external temperature. 

2. Body temperature is a measure of the metabolism - the general level of chemical activity within the body. 

3. The hypothalamus is the major center of the brain for regulating body temperature. It is sensitive to blood temperature changes of as little as 0.5 degrees Celsius and also reacts to nerve impulses received from nerve endings in the skin. 

4. The optimum temperature for chemical reactions to take place in the body is 98.6 degrees F. Above 105 F many body enzymes become denatured and chemical reactions cannot take place leading to death. Below 98.6 F chemical reactions slow down with various complications which can lead to death. 

5. Core = the internal body organs, particularly the heart, lungs, and brain. 
Periphery = the appendages, skin, and muscle tissue. 

6. Core temperature is the temperature that is essential to the overall metabolic rate of the body. The temperature of the periphery is not critical. 

<h2>How Your Body Regulates Core Temperature</h2>

1. Vasodilation - increases surface blood flow, increases heat loss (when ambient temperature is less that body temperature). Maximal vasodilation can increase cutaneous blood flow to 3000 ml/minute (average flow is 300-500 ml/minute). 

2. Vasoconstriction - decreases blood flow to periphery, decreases heat loss. Maximal vasoconstriction can decrease cutaneous blood flow to 30 ml/minute. 

3. Sweating - cools body through evaporative cooling 

4. Shivering - generates heat through increase in chemical reactions required for muscle activity. Visible shivering can maximally increase surface heat production by 500%. However, this is limited to a few hours because of depletion of muscle glucose and the onset of fatigue. 

5. Increasing/Decreasing Activity will cause corresponding increases in heat production and decreases in heat production. 

6. Behavioral Responses - putting on or taking off layers of clothing will result in heat regulation 

<h2>Hypothermia</h2>

1. Hypothermia - "a decrease in the core body temperature to a level at which normal muscular and cerebral functions are impaired." - Medicine for Mountaineering 

2. Conditions Leading to Hypothermia
<ul>
<li>Cold temperatures </li>
<li>Improper clothing and equipment </li>
<li>Wetness </li>
<li>Fatigue, exhaustion </li>
<li>Dehydration </li>

<li>Poor food intake </li>
<li>No knowledge of hypothermia </li>
<li>Alcohol intake - causes vasodilation leading to increased heat loss </li>
</ul>

3. What are "hypothermia" temperatures
<ul>

<li>Below freezing </li>
<li>40 degrees - Ex. Shenandoahs, wind and rain </li>
<li>60 degrees - Ex. Rayanna and hurricane </li>
<li>Any temperature less than 98.6 degrees can be linked to hypothermia (ex. hypothermia in
the elderly in cold houses) or peripheral circulation problems such as trench foot and
frostbite. </li>
</ul>

4. Signs and Symptoms of Hypothermia 

a. Watch for the "-Umbles" - stumbles, mumbles, fumbles, and grumbles which show changes in motor coordination and levels of consciousness 

b. Mild Hypothermia - core temperature 98.6 - 96 degrees F
<ul>
<li>Shivering - not under voluntary control </li>

<li>Can't do complex motor functions (ice climbing or skiing) can still walk & talk </li>
<li>Vasoconstriction to periphery </li>
</ul>

c. Moderate Hypothermia - core temperature 95 - 93 degrees F
<ul>
<li>Dazed consciousness </li>

<li>Loss of fine motor coordination - particularly in hands - can't zip up parka, due to restricted peripheral blood flow </li>
<li>Slurred speech </li>
<li>Violent shivering </li>
<li>Irrational behavior - Paradoxical Undressing - person starts to take off clothing, unaware s/he is cold </li>
<li>"I don't care attitude" - flattened affect </li>

</ul>

d. Severe Hypothermia - core temperature 92 - 86 degrees and below (immediately life threatening)
<ul>
<li>Shivering occurs in waves, violent then pause, pauses get longer until shivering finally ceases - because the heat output from burning glycogen in the muscles is not sufficient 
to counteract the continually dropping core temperature, the body shuts down on shivering to conserve glucose </li>
<li>Person falls to the ground, can't walk, curls up into a fetal position to conserve heat </li>

<li>Muscle rigidity develops - because peripheral blood flow is reduced and due to lactic acid and CO2 buildup in the muscles </li>
<li>Skin is pale </li>
<li>Pupils dilate </li>
<li>Pulse rate decreases </li>
<li>at 90 degrees the body tries to move into hibernation, shutting down all peripheral blood flow and reducing breathing rate and heart rate. </li>
<li>at 86 degrees the body is in a state of "metabolic icebox." The person looks dead but is still alive. </li>

</ul>

e. Death from Hypothermia 
<ul>
<li>Breathing becomes erratic and very shallow </li>
<li>Semi-conscious </li>
<li>Cardiac arrythmias develop, any sudden shock may set off Ventricular Fibrillation </li>
<li>Heart stops, death </li>

</ul>

5. How to Assess if someone is Hypothermic


<ul>
<li>If shivering can be stopped voluntarily = mild hypothermia </li>
<li>Ask the person a question that requires higher reasoning in the brain (count backwards from 100 by 9's). If the person is hypothermic, they won't be able to do it. [Note: there are also other conditions such as altitude sickness that can also cause the same condition.] </li>
<li>If shivering cannot be stopped voluntarily = moderate - severe hypothermia </li>
<li>If you can't get a radial pulse at the wrist it indicates a core temp below 90 - 86 degrees </li>

<li>The person may be curled up in a fetal position. Try to open their arm up from the fetal position, if it curls back up, the person is alive. Dead muscles won't contract only live muscles. </li>
</ul>
<table border="1">
<tr>
<th>Stage</th>
<th>Core Temperature</th>
<th>Signs & Symptoms</th>
</tr>
<tr>
<td rowspan="2" bgcolor="#80FFFF">Mild Hypothermia</td>
<td bgcolor="#80FFFF">99? - 97?F</td>
<td bgcolor="#80FFFF">Normal, shivering can begin</td>
</tr>
<tr>
<td bgcolor="#80FFFF">97? - 95?F</td>
<td bgcolor="#80FFFF">Cold sensation, goose bumps, unable to perform complex tasks with hands, shiver can be mild to severe, hands numb</td>
</tr>
<tr>
<td rowspan="2">Moderate Hypothermia</td>
<td>95? - 93?F</td>
<td>Shivering, intense, muscle incoordination becomes apparent, movements slow and labored, stumbling pace, mild confusion, may appear alert. Use sobriety test, if unable to walk a 30 foot straight line, the person is hypothermic.</td>
</tr>
<tr>
<td>93? - 90?F</td>
<td>Violent shivering persists, difficulty speaking, sluggish thinking, amnesia starts to appear, gross muscle movements sluggish, unable to use hands, stumbles frequently, difficulty speaking, signs of depression, withdrawn.</td>
</tr>
<tr>
<td rowspan="4" bgcolor="#00FFFF">Severe Hypothermia</td>
<td bgcolor="#00FFFF">90? - 86?F</td>
<td bgcolor="#00FFFF">Shivering stops, exposed skin blue of puffy, muscle coordination very poor, inability to walk, confusion, incoherent/irrational behavior, but may be able to maintain posture and appearance of awareness</td>
</tr>
<tr>
<td bgcolor="#00FFFF">86? - 82?F</td>
<td bgcolor="#00FFFF">Muscle rigidity, semiconscious, stupor, loss of awareness of others, pulse and respiration rate decrease, possible heart fibrillation</td>
</tr>
<tr>
<td bgcolor="#00FFFF">82? - 78?F</td>
<td bgcolor="#00FFFF">Unconscious, heart beat and respiration erractic, pulse may not be palpable</td>
</tr>
<tr>
<td bgcolor="#00FFFF">78? - 75?F</td>
<td bgcolor="#00FFFF">Pulmonary edema, cardiac and respiratory Failure,death. Death may occur before this temperature is reached.</td>
</tr>
</table>

<hr />

<h2>Treating Hypothermia</h2>

The basic principles of rewarming a hypothermic victim are to conserve the heat they have and replace the body fuel they are burning up to generate that heat. If a person is shivering, they have the ability to rewarm themselves at a rate of 2 degrees C per hour. 

<h2>Mild - Moderate Hypothermia</h2>

1. Reduce Heat Loss

<ul>
<li>Additional layers of clothing </li>
<li>Dry clothing </li>
<li>Increased physical activity </li>
<li>Shelter </li>
</ul>

2. Add Fuel & Fluids 

It is essential to keep a hypothermic person adequately hydrated and fueled. 

a. Food types
<ul>
<li>Carbohydrates - 5 calories/gram - quickly released into blood stream for sudden brief heat surge - these are the best to use for quick energy intake especially for mild cases of hypothermia </li>
<li>Proteins - 5 calories/gram - slowly released - heat given off over a longer period </li>
<li>Fats - 9 calories/gram - slowly released but are good because they release heat over a long period, however, it takes more energy to break fats down into glucose - also takes more water to break down fats leading to increased fluid loss </li>
</ul>

b. Food intake
<ul>
<li>Hot liquids - calories plus heat source </li>
<li>Sugars (kindling) </li>
<li>GORP - has both carbohydrates (sticks) and protiens/fats (logs) </li>
</ul>

c. Things to avoid

<ul>
<li>Alcohol - a vasodilator - increases peripheral heat loss </li>
<li>Caffeine - a diuretic - causes water loss increasing dehydration </li>
<li>Tobacco/nicotine - a vasoconstrictor, increases risk of frostbite </li>
</ul>

3. Add Heat
<ul>
<li>Fire or other external heat source </li>

<li>Body to body contact. Get into a sleeping back, in dry clothing with a normothermic person in lightweight dry clothing </li>
</ul>

<h2>Severe Hypothermia</h2>


1. Reduce Heat Loss


<ul>
<li>Hypothermia Wrap: The idea is to provide a shell of total insulation for the patient. No matter how cold, patients can still internally rewarm themselves much more efficiently than any external rewarming. Make sure the patient is dry, and has a polypropylene layer to minimize sweating on the skin. The person must be protected from any moisture in the environment. Use multiple sleeping bags, wool blankets, wool clothing, Ensolite pads to create a minimum of 4" of insulation all the way around the patient, especially between the patient and the ground. Include an aluminum "space" blanket to help prevent radiant heat loss, and wrap the entire ensemble in plastic to protect from wind and water. If someone is truly hypothermic, don't put him/her naked in a sleeping bag with another person. </li>
</ul>

2. Add Fuel & Fluids
<ul>
<li>Warm Sugar Water - for people in severe hypothermia, the stomach has shut down and will not digest solid food but can absorb water and sugars. Give a dilute mixture of warm water with sugar every 15 minutes. Dilute Jello? works best since it is part sugar and part protein. This will be absorbed directly into the blood stream providing the necessary calories to allow the person to rewarm themselves. One box of Jello = 500 Kilocalories of heat energy. Do not give full strength Jello even in liquid form, it is too concentrated and will not be absorbed. </li>

<li>Urination - people will have to urinate from cold diuresis. Vasoconstriction creates greater volume pressure in the blood stream. The kidneys pull off excess fluid to reduce the pressure. A full bladder results in body heat being used to keep urine warm rather than vital organs. Once the person has urinated, it precious body heat will be used to maintain the temperature of vital organs. So in the end urinating will help conserve heat. You will need to help the person urinate. Open up the Hypothermia Wrap enough to do this and then cover them back up. You will need to keep them hydrated with the dilute Jello solution described above. </li>
</ul>

3. Add Heat 

Heat can be applied to transfer heat to major arteries - at the neck for the carotid, at the armpits for the brachial, at the groin for the femoral, at the palms of the hands for the arterial arch.
<ul>
<li>Chemical heat packs such as the Heat Wave? provides 110 degrees F for 6-10 hours. </li>

<li>Hot water bottles, warm rocks, towels, compresses </li>
<li>For a severely hypothermic person, rescue breathing can increase oxygen and provide internal heat. </li>
</ul>



Hypothermia Wrap


<h2>Afterdrop</h2>

Is a situation in which the core temperature actually decreases during rewarming. This is caused by peripheral vessels in the arms and legs dilating if they are rewarmed. This dilation sends this very cold, stagnate blood from the periphery to the core further decreasing core temperature which can lead to death. In addition, this blood also is very acetic which may lead to cardiac arrythmias and death. Afterdrop can best be avoided by not rewarming the periphery. Rewarm the core only! Do not expose a severely
hypothermic victim to extremes of heat. 

<h2>CPR & Hypothermia</h2>

When a person is in severe hypothermia they may demonstrate all the accepted clinical signs of death:
<ul>
<li>Cold </li>
<li>Blue skin </li>
<li>Fixed and dilated pupils </li>

<li>No discernable pulse </li>
<li>No discernable breathing </li>
<li>Comatose & unresponsive to any stimuli </li>
<li>Rigid muscles </li>
</ul>

But they still may be alive in a "metabolic icebox" and can be revived. You job as a rescuer is to rewarm the person and do CPR if indicated. A hypothermia victim is never cold and dead only warm and dead. During severe hypothermia the heart is hyperexcitable and mechanical stimulation (such as CPR, moving them or Afterdrop) may result in fibrillation leading to death. As a result CPR may be contraindicated for some hypothermia situations: 

1. Make sure you do a complete assessment of heart rate before beginning CPR.
Remember, the heart rate may be 2-3/minute and the breathing rate 1/30 seconds. Instituting cardiac compressions at this point may lead to life-threatening arrythmias. Check the carotid pulse for a longer time period (up to a minute) to ascertain if there is some slow heartbeat. Also, even though the heart is beating very slowly, it is filling completely and distributing blood fairly effectively. External cardiac compressions only are 20-30% effective. Thus, with its severely decreased demands, the body may be able to satisfy its circulatory needs with only 2-3 beats per minute. Be sure the pulse is absent before beginning CPR. You will need to continue to do CPR as you rewarm the person.


2. Ventilation may have stopped but respiration may continue - the oxygen demands for the body have been so diminished with hypothermia that the body may be able to survive for some time using only the oxygen that is already in the body. If ventilation has stopped,
artificial ventilation may be started to increase available oxygen. In addition, blowing warm air into the persons lungs may assist in internal rewarming. 

3. CPR Procedures
<ul>
<li>Check radial pulse, between 91.4 and 86 degrees F this pulse disappears </li>

<li>Check for carotid pulse - wait at least a full minute to check for very slow heartbeat </li>
<li>If pulse but not breathing or slow breathing, give rescue breathing (also adds heat). </li>
<li>If no discernible heartbeat begin CPR and be prepared to continue - persons with hypothermia have been given CPR for up to 3.5 hours and have recovered with no neurological damage </li>
<li>Begin active rewarming </li>
</ul>

<h2>Cold Injuries</h2>

Tissue temperature in cold weather is regulated by two factors, the external temperature and the internal heat flow. All cold injuries described below are intimately connected with the degree of peripheral circulation. As peripheral circulation is reduced to prevent heat loss to the core these conditions are more likely to occur. 

1. Factors influencing cold injuries
<ul>
<li>Low ambient temperature </li>
<li>Wind chill - increases rate of freezing dramatically </li>
<li>Moisture - wet skin freezes at a higher temp than dry </li>

<li>Insulation </li>
<li>Contact with metal or supercooled liquids (white gas) </li>
<li>Exposed skin </li>
<li>Vasodilation </li>
<li>Vasoconstriction </li>
<li>Previous cold injuries </li>

<li>Constricting garments </li>
<li>Local pressure </li>
<li>Cramped position </li>
<li>Body type </li>
<li>Dehydration </li>
<li>Women do better in cold than men (greater subcutaneous body fat) </li>

<li>Caloric intake </li>
<li>Diabetes, some medications </li>
<li>Alcohol </li>
<li>Caffeine, nicotine </li>
</ul>

2. Cold-induced Vasodilation - When a hand or foot is cooled to 59 degrees F, maximal vasoconstriction and minimal blood flow occur. If cooling continues to 50 degrees, vasoconstriction is interrupted by periods of vasodilation with an increase in blood and
heat flow. This "hunting" response recurs in 5-10 minute cycles to provide some protection from cold. Prolonged, repeated exposure increases this response and offers some degree of acclimatization. Ex. Eskimos have a strong response with short intervals in between. 

3. Pathophysiology of Tissue Freezing - As tissue begins to freeze, ice crystals are formed within the cells. As intracellular fluids freeze, extracellular fluid enters the cell and there is an increase in the levels of extracellular salts due to the water
transfer. Cells may rupture due to the increased water and/or from tearing by the ice crystals. Do not rub tissue; it causes cell tearing from the ice crystals. As the ice melts there is an influx of salts into the tissue further damaging the cell membranes. Cell destruction results in tissue death and loss of tissue. Tissue can't
freeze if the temperature is above 32 degrees F. It has to be below 28 degrees F because of the salt content in body fluids. Distal areas of the body and areas with a high surface to volume ratio are the most susceptible (e.g ears, nose, fingers and toes - this little rhyme should help remind you what to watch out for in yourself and others).
<ul>
<li>Surface frostbite generally involves destruction of skin layers resulting in blistering and minor tissue loss. Blisters are formed from the cellular fluid released when cells rupture. </li>
<li>Deep frostbite can involve muscle and bone </li>
</ul>

<table border="1" cellpadding="5">
<tr>
<th> </th>
<th>Cold Response</th>
<th>Mild Frostnip</th>
<th>Superficial Frostbite</th>
<th>Deep Frostbite</th>

</tr>
<tr>
<td>Sensation</td>
<td>Painful</td>
<td>May have sensation</td>
<td>Numb</td>
<td>Numb</td>

</tr>
<tr>
<td>Feels</td>
<td>Normal</td>
<td>Normal</td>
<td>Soft</td>
<td>Hard</td>

</tr>
<tr>
<td>Color</td>
<td>Red</td>
<td>White</td>
<td>White</td>
<td>White</td>

</tr>
</table>

<hr />

4. Cold Response


<ul>
<li>Circulation is reduce to the are to prevent heat loss. </li>
<li>The area may be pale, cold. </li>

<li>It may have sensation or be numb. </li>
</ul>

5. Frostnip


<ul>
<li>Freezing of top layers of skin tissue </li>
<li>It is generally reversible </li>
<li>White, waxy skin, top layer feels hard, rubbery but deeper tissue is still soft </li>

<li>Numbness </li>
<li>Most typically seen on cheeks, earlobes, fingers, and toes </li>
</ul>

Treatment
<ul>
<li>Rewarm the area gently, generally by blowing warm air on it or placing the area against a warm body part (partner's stomach or armpit) </li>
<li>Do not rub the area - this can damage the effected tissue by having ice crystals tear the cell </li>

</ul>

6. Frostbite


<ul>
<li>Skin is white and "wooden" feel all the way through </li>
<li>Superficial frostbite includes all layers of skin </li>
<li>Numbness, possible anesthesia </li>

<li>Deep frostbite can include freezing of muscle and/or bone, it is very difficult to rewarm the appendage without some damage occurring </li>
</ul>


Treatment


<ul>
<li>Superficial frostbite may be rewarmed as frostnip if only a small area is involved </li>
<li>If deep frostbite, see below for rewarming technique </li>
</ul>


7. Rewarming of Frostbite


<ul>
<li>Rewarming is accomplished by immersion of the effected part into a water bath of 105 - 110 degrees F. No hotter or additional damage will result. This is the temperature which is warm to your skin. Monitor the temperature carefully with a thermometer. Remove constricting clothing. Place the appendage in the water and continue to monitor the water temperature. This temperature will drop so that additional warm water will need to be added to maintain the 105 - 110 degrees. Do not add this warm water directly to the injury. The water will need to be circulated fairly constantly to maintain even temperature. The effected appendage should be immersed for 25 - 40 minutes. Thawing is complete when the part is pliable and color and sensation has returned. Once the area is rewarmed, there can be significant pain. Discontinue the warm water bath when thawing is complete. </li>
<li>Do not use dry heat to rewarm. It cannot be effectively maintained at 105 - 110 degrees and can cause burns further damaging the tissues. </li>

<li>Once rewarming is complete the injured area should be wrapped in sterile gauze and protected from movement and further cold. </li>
<li>Once a body part has been rewarmed it cannot be used for anything. Also it is essential that the part can be kept from refreezing. Refreezing after rewarming causes extensive tissue damage and may result in loss of tissue. If you cannot guarantee that the tissue will stay warm, do not rewarm it. Mountaineers have walked out on frozen feet to have them rewarmed after getting out with no tissue loss. Once the tissue is frozen the major harm has been done. Keeping it frozen will not cause significant additional damage. </li>
</ul>

8. Special Considerations for Frostbite

<ul>
<li>If the person is hypothermic and frostbitten, the first concern is core rewarming. Do not rewarm the frostbitten areas until the core temp approaches 96 degrees. </li>
<li>No alcohol - vasodilation may increase fluid buildup </li>
<li>No smoking - nicotine as a vasoconstrictor may increase chances for developing frostbite </li>
<li>Liquids such as white gas can "supercool" in the winter (drop below their freezing point but not freeze). White gas also evaporates quickly into the air. Spilling supercooled white gas on exposed skin leads to instant frostbite from evaporative cooling. Always were gloves when handling fuel. </li>

<li>Touching metal with bare skin can cause the moisture on your skin to freeze to the metal. (In really cold conditions, metal glasses frames can be a problem). When you pull away, you may leave a layer of skin behind. Don't touch metal with bare skin. </li>
</ul>

9. Trench Foot - Immersion Foot 

Trench foot is a process similar to chillblains. It is caused by prolonged exposure of the feet to cool, wet conditions. This can occur at temperatures as high as 60 degrees F if the feet are constantly wet. This can happen with wet feet in winter conditions or wet feet in much warmed conditions (ex. sea kayaking). The mechanism of injury is as follows:
wet feet lose heat 25x faster than dry, therefore the body uses vasoconstriction to shut down peripheral circulation in the foot to prevent heat loss. Skin tissue begins to die because of lack of oxygen and nutrients and due to buildup of toxic products. The skin is initially reddened with numbness, tingling pain, and itching then becomes pale and mottled and finally dark purple, grey or blue. The effected tissue generally dies and sluffs off. In severe cases trench foot can involve the toes, heels, or the entire foot. If circulation is impaired for > 6 hours there will be permanent damage to tissue. If circulation is impaired for > 24 hours the victim may lose the entire foot. Trench Foot cuases permanent damage to the circulatory system making the person more prone to cold related injuries in that area. A similar phenomenon can occur when hands are kept wet for long periods of time such as kayaking with wet gloves or pogies. The damage to the
circulatory system is known as Reynaud's Phenomenon. 

Treatment and Prevention of Trench foot

<ul>
<li>Includes careful washing and drying of the feet, gentle rewarming and slight elevation. Since the tissue is not frozen as in severe frostbite it is more susceptible to damage by walking on it. Cases of trench foot should not walk out; they should be evacuated by litter. Pain and itching are common complaints. Give ibuprofen or other pain medication. </li>
<li>Prevention is the best approach to dealing with trench foot. Keep feet dry by wearing appropriate footwear. Check your feet regularly to see if they are wet. If your feet get wet (through sweating or immersion), stop and dry your feet and put on dry socks. Periodic air drying, elevation, and massage will also help. Change socks at least once a day and do not sleep with wet socks. Be careful of tight socks which can further impair peripheral circulation. Foot powder with aluminum hydroxide can help. High altitude mountaineers will put antiperspirant on their feet for a week before the trip. The active ingredient, aluminum hydroxide will keep your feet from sweating for up to a month and their are no confirmed contraindications for wearing antiperspirant. [Some studies have shown links between alumnium in the body and Alzheimers.] Vapor barrier socks may increase the possibility of trenchfoot. When you are active and you are wearing a vapor barrier sock, you must carefully monitor how you sweat. If you are someone who sweats a lot with activity, your foot and polypropylene liner sock may be totally soaked before the body shuts down sweating. Having this liquid water next to the skin is going to lead to increased heat loss. If you don?t sweat much, your body may shut down perspiration at the foot before it gets actually wet. This is when the vapor barrier system is working. You must experiment to determine if vapor barrier systems will work for you. </li>
</ul>

10. Chillblains 

<ul>
<li>Caused by repeated exposure of bare skin to temperatures below 60 degrees </li>
<li>Redness and itching of the effected area </li>
<li>Particularly found on cheeks and ears, fingers and toes </li>
<li>Women and young children are the most susceptible </li>
<li>The cold exposure causes damage to the peripheral capillary beds, this damage is
permanent and the redness and itching will return with exposure </li>

</ul>
11. Avoiding Frostbite and Cold related Injuries 

<ul>
<li>"Buddy system" - keep a regular watch on each other's faces, cheeks, ears for
signs of frostnip/frostbite </li>
<li>Keep a regular "self check" for cold areas, wet feet, numbness or anesthesia </li>

<li>If at any time you discover a cold injury, stop and rewarm the area (unless doing so places you at greater risk). </li>
</ul>

12. Eye Injuries 

a. Freezing of Cornea
<ul>
<li>Caused by forcing the eyes open during strong winds without goggles </li>
<li>Treatment is very controlled, rapid rewarming e.g. placing a warm hand or compress over the closed eye. After rewarming the eyes must be completely covered with patches for 24 - 48 hours. </li>

</ul>

b. Eyelashes freezing together
<ul>
<li>Put hand over eye until ice melts, then can open the eye </li>
</ul>

c. Snowblindness
<ul>
<li>Sunburn of the eyes </li>
<li>Prevention by wearing good sunglasses with side shields or goggles. Eye protection from sun is just as necessary on cloudy or overcast days as it is in full sunlight when you are on snow. Snow blindness can even occur during a snow storm if the cloud cover is thin. </li>
</ul>


Symptoms


<ul>
<li>Occur 8-12 hours after exposure </li>
<li>Eyes feel dry and irritated, then feel as if they are full of sand, moving or blinking becomes extremely painful, exposure to light hurts the eyes, eyelids may swell, eye redness, and excessive tearing </li>

</ul>


Treatment


<ul>
<li>Cold compresses and dark environment </li>
<li>Do not rub eyes </li>
</ul>
<hr />


BIBLIOGRAPHY


<ul>
<li>The Backpacker's Field Manual, Rick Curtis, Random House, New York, 2005.</li>
<li>Hypothermia: Causes, Effects, and Prevention, Robert Pozos, David Born, New Century, 1982. </li>
<li>Management of Wilderness and Environmental Emergencies, Paul Auerbach, Edward Geehr, Macmillan, 1983. </li>
<li>Medicine for Mountaineering, James Wilkerson, The Mountaineers, 1992. </li>

<li>Hypothermia - Death by Exposure, William Forgey, ICS, 1985. </li>
<li>Hypothermia, Frostbite, and other Cold Injuries, James Wilkerson, Cameron Bangs, John Hayward, The Mountaineers, 1986 </li>
<li>Medicine for the Backcountry, Buck Tilton and Frank Hubbell, ICS Books, 1994. </li>
</ul>

**JJackson** · December 31, 2006, 08:58 PM

Re: PREVENTING INDOOR HYPOTHERMIA

A surprisingly efficient low tech (and not too expensive) solution is a small one or two man tents. Erected indoors these will warm up with body heat or small stove and make an enormous difference. Try it on a cold night (P.S. remember to turn off the central heating).

**Lynda** · January 1, 2007, 08:55 PM

Re: PREVENTING INDOOR HYPOTHERMIA

This is good information, with one exception. The article says to rewarm @ 105-110 degrees. Anyone who has a spa-hot tub knows 110 F. feels scalding to 98.6 skin, and is dangerous. Spa manufacturers recommend 100-104.

110* F. will boil you like a lobster.

Another hint for staying warm: Home Depot and similar stores have a product in rolls called Reflectix that can be used over windows, to make tents, on feet, inside a sleeping bag, or as a body wrap. It's space blanket material with a thin insulation core. Love the stuff.

**Jonesie** · January 4, 2007, 10:55 AM

Re: PREVENTING INDOOR HYPOTHERMIA

Here is some good information on dressing yourself for cold weather. Remember, all utilities may be non-functioning for parts of the pandemic and also the post-pandemic period. Utilities may not be reliable for a 3 year period.
If you do not have adequate clothing and bedding to use indoors, you may well succumb to 'indoor hypothermia'.

If you have overlooked clothing and bedding in your preps, be sure to go out and buy what is needed NOW.
----------------------------------------------------------------------------------------------------------

12 Tips to Help You Choose Warm Clothes

In a 4 season climate, its nice to know how to dress warmly enough to stay comfortable outdoors. Here are some tips for doing so.

1. Dress in layers.

The more layers, the better. Dressing in layers of clothing does several things for you:

Layers fill up the space between you and your winter coat with insulation. An undershirt, a shirt, and a sweater each represent one layer. Your winter coat is yet another layer. The more layers of insulation, the better.

Layers tend to trap air better. If you have only an overcoat on, the warm air next to your body tends to leak out of the top and bottom of the overcoat as you make body movements. Layers help to hold this air in.

Layers allow you to regulate your body temperature more accurately. If you get too warm, you can always open up a layer -- starting with opening up the top of your overcoat and progressively opening up more and more layers as you get warmer and warmer.

2. Favor natural materials.

In my opinion, there is nothing warmer and lighter than a down overcoat. If you can, buy one that is rated to a certain temperature such as 20 degrees below zero Fahrenheit.

3. Don't get over-sold on synthetic materials.

Synthetic materials often come highly recommended. Before you buy synthetic materials, however, be aware of the following:

Wool will keep you warm even when it is wet. I know of no synthetic material that will do this.

Natural materials tend to breath better. This can be critical when you start to work up a little bit of a sweat and need to evaporate this sweat so that you don't become cold later when you are a little less active.

One exception is the value synthetics add as wind-breaking materials. It sometimes makes sense, for example, to have a pair of wool gloves (perhaps with leather palms for wear) covered by larger-than-your size mittens that have a nylon shell. This will keep your hands very warm.

4. Be aware that you lose more heat through your head than any other body part.

This can be very deceptive. Your head never feels cold. Why? Because your body sends more heat to your head than any other body part to protect it.

Keeping your brain warm is so critical that your body will sacrifice any other body part before it will let the brain get cold.

Just because your head does not feel cold does not mean you are not losing heat off the top of your head. Remember this forever! You will not feel yourself losing heat off the top of your head, but you are!

The reason your feet and hands are cold is because you are losing heat in the head area. Why? Because hands and feet are low priority and your head is top priority.

This is the body's system for rationing its limited heat supply. Because your head is given top priority when it comes to heat supply, it never feels cold even though it is in fact a giant heat dissipation module.

Remember! Your head leaks heat. Plug the leak.

If you will prioritize keeping your head warm, you will have won half the battle in keeping your body warm.

5. The dumber your head-gear looks, the warmer it is.

I was recently shopping at L.L. Beans. A man was looking at a bombardier hat with a leather cover and a sheepskin lining.

A woman who appeared to be his wife said to him, "Forget it! You're not wearing it!" Grimly, he put it back. He had just barely started to look.

The hat would have gone well with the character Jim Carey played in the film Dumb and Dumber. As dumb as it looks, it is also very warm.

Yes, head-gear that dramatically alters your appearance is incredibly warm. The converse is also true. Cool-looking winter hats are just that -- a little too cool temperature-wise.

Why do you think those Russian women wear those big fur hats when it's 20 below zero? Because fur is incredibly warm, that's why.

6. Keep your feet warm.

Your feet are in contact with the cold ground. You should wear well-insulated boots.

Again, favor natural materials. Wear wool socks if you can find them and layer them if necessary.

Sheep skin boots can also be quite warm.

7. Keep your neck warm.

A scarf around the neck or a jacket that zips up to your neck will do.

There are 2 important reasons for covering your neck:

You want to leave as little skin exposed as possible. This is the obvious reason.

A less obvious reason is that you want to seal the top of your jacket so that air does not leak out of the body of your jacket. You lose a lot of heat when the top of your jacket is basically an open hole surrounding your neck. If you were a boat, you'd sink.

Patch up the leaks wherever you can. Be sure to buy a jacket that has velcro seals on the cuffs of the sleeves so that you get a tight seal against the cold around your wrists.

8. Prioritize! Decide in advance which body parts you wish to keep warmest.

This was taught to me by a lady from Norway. She says that keeping your priorities straight will help keep you warmer. Some body parts are more important than others.

Here is how I suggest you prioritize based on what I learned from her:

First, you want to keep your torso warm.
Second, your want to keep your head warm.
Third, you want to keep your feet warm.
Fourth, you want to keep your neck warm.
Fifth, you want to keep your hands warm.
Sixth, you want to keep your legs warm.

By focusing on what is most important first, you are likely to stay warmer. Why? Because ignoring a very important priority area, such as the head, will make you cold very quickly.

9. Make sure you don't sweat.

If you get too warm. you sweat. This is very bad. If you sweat, you get wet. If you get wet, you get cold.

How do you avoid sweating? Make sure you peel off your layers as you start to get warm. A very fast way to cool off is to open up your jacket. Another is to take off your hat.

Anything that helps you to radiate heat will help you to cool down. Taking off your mittens turns your fingers into radiator prongs radiating heat. Taking your hat off turns your head into one giant radiator prong radiating heat.

The key is to stay on top of it. At the first sign of excessive warmth, start opening things up. Usually this happens when you are doing something that causes you to exert yourself, such as climbing a hill.

10. Keep your face warm by keeping the rest of your body warm.

Yes, you can cover your face with a scarf or a face mask. Do so if it is cold enough and you have to. However, I find covering my face to be uncomfortable.

I prefer to employ another tactic. I like to keep the rest of my body so warm that I can afford to lose warmth through my face.

Think of it as a bank account. Warmth you preserve with other parts of your body can be spent on your face. Call this tactic saving face if you need an easy mnemonic.

11. Wear long underwear.

Besides providing an extra layer, long underwear saves your legs if all you are wearing are blue jeans.

12. Buy a good winter coat.

I've saved the best suggestion for last. Here are some of the features you want in a winter coat:

Make sure it features down insulation. In spite of commercial advertising to the contrary, there is nothing warmer than down -- in my opinion.

Make sure it is rated. My coat is from L.L. Beans. It is rated to 20 degrees below zero (fahrenheit). It is quite warm. You can do even better than this at a mountaineering store if you need to.

Note that the ratings on coats are generally geared towards moderate activity. If you are planning on standing around gazing at the stars through your telescope, you may need to buy something that is even warmer.

Make sure it has a hood. This is important because it represents yet another layer. You should wear both a hat and a hood if it is very cold.

Ideally the hood will stick out in front of your face just like the hoods of Antarctic explorers you see in National Geographic. This traps air near your face. The fur lining that lines the hood is a further air trap. A natural fur can provide a further benefit; it reflects heat back to your face.

Unfortunately for warmth, the fur on my hood is cotton and acrylic.

Make sure that all openings on the jacket seal. This includes the top of the jacket and the sleeves. There should be a pull string that lets you adjust the waist so that you don't lose air out of the bottom.

Buy a coat that is long enough. I special ordered mine in a long size. The racks in the store did not carry one that was long enough to suit me.

Ideally, I want a winter coat to extend far down on my thighs and the sleeves to reach down to my hands.

Conclusion

How you feel about wintertime is largely dependent on how good a job you do of keeping yourself warm. It's a modest ambition -- wanting to stay warm. But it is very important to your wintertime morale.

©Edward Abbott, 2003-2004. All rights reserved. Revised May 4, 2004.

Questions or comments? Email me at ed@WebSiteRepairGuy.com.

12 Tips to Help You Choose Warm Clothes

http://www.websiterepairguy.com/articles/household_tips/stay_warm.html

**AlaskaDenise** · January 4, 2007, 09:47 PM

Re: PREVENTING INDOOR HYPOTHERMIA

Keep your head warm at night also - wear a sleep cap.

.

**Jonesie** · January 30, 2007, 06:06 PM

Re: PREVENTING INDOOR HYPOTHERMIA

I just tested my down vests and sheepskin footwear by turning the heat off in my house for 24 hours again. (I let it drop down to 55 degrees F.) I arrived at the following conclusion: I need down, wool, and sheepskin clothing to keep warm, or I will not make it throught a pandemic winter.

If you live in an area where the temperature drops below 65 degrees, you will need 2 down vests to keep your body core warm. (If you loose heat in your residence for 24 hours or more).
I had just one down vest, a lightweight vest with not enough down in it to handle a temperature drop to 55 degrees F.
So I went out and bought a heavyweight down vest which solved the problem. Then I was warm as toast.

Just turn your heat down to 55 degrees F. and you'll see what I mean.
Down vests are being reduced at most retail stores now. They are clearing them out to make room for spring fashions, so now is the ideal time to purchase them. They are very lightweight and allow for ease of movement of the arms. My wool sweaters are a close second, but I need 3 or 4 of them to keep me as warm as just one down vest.

You want to keep your body core warm during the Pandemic, when gas and electrical heat may fail.

Your feet must not be allowed to get cold. It puts too much stress on the body. As the temperature dropped in my house, I had to switch from shoes and socks to heavyweight wool hunting socks and sheepskin slippers to keep my feet warm.
So purchase a few pair of sheepskin or shearling slippers online now from various sporting goods stores. They will keep your feet warm and dry, as will sheepskin boots. Nothing else will keep your feet as warm as genuine shearling & sheepskin. The sheepskin and down items will run around $35 to $50 each. They are available on ebay also. A very wise investment.

The sheepskin products are imported from New Zealand, Australia and China. Those countries will all close their ports during a Pandemic, so get them now.
And if you plan on working in an unheated office building, you will need very warm clothing. Consider buying many wool sweaters and about 3 dozen pair of merino wool socks of varying weights to tide you over a pandemic and post-pandemic period of 2 - 3 years.

The trade in feathers and down may cease during a pandemic. I found I needed 2 down comforters and a feather mattress to keep warm during the night. Plus 2 wool blankets! There are many people selling down bedding on ebay.

You sure want to avoid the following problems in your household:

Peripheral blood flow during rewarming from mild hypothermia in humans.
Savard GK, Cooper KE, Veale WL, Malkinson TJ.

During the initial stages of rewarming from hypothermia, there is a continued cooling of the core, or after-drop in temperature, that has been attributed to the return of cold blood due to peripheral vasodilatation, thus causing a further decrease of deep body temperature. To examine this possibility more carefully, subjects were immersed in cold water (17 degrees C), and then rewarmed from a mildly hypothermic state in a warm bath (40 degrees C). Measurements of hand blood flow were made by calorimetry and of forearm, calf, and foot blood flows by straingauge venous occlusion plethysmography at rest (Ta = 22 degrees C) and during rewarming. There was a small increase in skin blood flow during the falling phase of core temperature upon rewarming in the warm bath, but none in foot blood flow upon rewarming at room air, suggesting that skin blood flow seems to contribute to the after-drop, but only minimally. Limb blood flow changes during this phase suggest that a small muscle blood flow could also have contributed to the after-drop. It was concluded that the after-drop of core temperature during rewarming from mild hypothermia does not result from a large vasodilatation in the superficial parts of the periphery, as postulated. The possible contribution of mechanisms of heat conduction, heat convection, and cessation of shivering thermogenesis were discussed.

PMID: 3968020 [PubMed - indexed for MEDLINE]

Peripheral blood flow during rewarming from mild hypothermia in humans - PubMed

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?itool=abstractplus&db=pubmed&cmd=Retrieve&dopt=abstractplus&list_uids=3968020

During the initial stages of rewarming from hypothermia, there is a continued cooling of the core, or after-drop in temperature, that has been attributed to the return of cold blood due to peripheral vasodilatation, thus causing a further decrease of deep body temperature. To examine this possibilit …

**Jonesie** · February 4, 2007, 07:44 PM

Re: PREVENTING INDOOR HYPOTHERMIA

If you live in one of the northern states, this week is an ideal time to take an inventory of your cold weather gear.
The temperatures are 23 below zero in some states, with wind chills near 40 below zero this week.
Should a pandemic wave occur during a severe cold spell, and should there be no gas for your vehicle, and an emergency arise where you would have to walk a mile or more on an errand, it is absolutely necessary to have the proper clothing to protect yourself from frostbite, hypothermia, and death.
I found a nice informative site that outlines for you the necessary clothing you will need to survive the elements.
If you do not have the suggested clothing in your home, please do yourself a great service and purchase the items you need as soon as possible:

http://www.hudsontrail.com/brochure.php?brochureid=5

The Importance of Layering
Protective clothing is the most important equipment you will carry into the backcountry. During hostile weather, your attire must create a comfortable and safe personal environment to withstand any number of varying weather conditions. This thin buffer against the elements defends your very survival, so clothing must be chosen and fitted with care.

No all-purpose garment can adapt to varying climates or temperatures, but versatile garments can contribute to a system of layered clothing that can be adjusted to any situation. The key to layering is to have breathable and moisture managing warm layers that can be peeled away or layered on top of one another when necessary. When you over-exert and become sweaty, take a layer off and put it in your pack. When you begin to get chilly, put a layer on. Versatile outdoor clothing adapts to protect you from thermal stress, rain, snow and wind.

Body Physiology
When conditions are unfavorable, your body adjusts energy production and circulatory priorities to maintain life. Circulation to the extremities is curtailed if core temperatures drop slightly as the brain and central nervous system become top priority.

The key to comfort and survival in winter conditions is to maintain a near constant skin temperature. If the skin temperature drops, you’re losing energy and the internal body controls go into high gear to produce more heat. If the skin temperature is too high, sweating starts to function as an evaporative cooling system. Both conditions are not favorable for health or safety in the cold.

To maintain comfort and energy production you also need to pay attention to your body’s nutritional requirements for sustained physical effort. Typically, extended activity requires a 4,000 calorie diet containing 50% carbohydrates, 30% proteins and 20% fats. Carbohydrates are readily converted to usable energy, while proteins and fats require energy for digestion. Try to maintain an intake of carbohydrates throughout the day, “eating your way down the trail,” as author Robert Wood put it. Your body will work best regulating itself with the proper intake of nutrients throughout the day. Your body does the best job of digesting food while at rest during cold weather, so it makes sense to eat your heaviest meal in the evening, as opposed to breakfast, on days of high activity (especially when you are camping in the backcountry). The warmth of your sleeping bag is the best environment for renewing your energy supply to prepare for the next day’s hike.

Tropical & Desert Climates
Clothing protects from the heat as well as the cold. Clothing for extreme heat must be loose fitting, moisture wicking, and vented to pump the hot air out. It should be light colored to reflect solar heat and rugged enough to resist abrasion from the terrain. Use sunblock on all exposed skin and a wide brimmed hat to prevent sunburn on your scalp and face.

Winter-Weight Attire
Proper clothing for any winter activity consists of three basic layers: the skin layer, insulating layers, and shell outerwear. The skin layer should insulate, but more importantly, wick moisture away from the skin as perspiration is produced. This reduces evaporative heat loss. The insulating layers should be fleece, wool, goosedown or synthetic fibers. Cotton should not be used for winter wilderness dressing as it retains too much moisture. Shell outerwear must be waterproof, breathable and windproof to protect you from the elements and still let body vapor escape.

The Skin Layer
Winter underwear is not only the first layer in your outdoor wardrobe, it is the most important. Underwear should trap an insulating layer of air next to the skin and also transport any moisture build-up to the outer clothing where it can be vented to the outside.

Synthetics, silks and wool/synthetic blends are particularly good at drawing moisture away from the skin to eliminate evaporative skin cooling, a major cause of heat loss. These fabrics are also quick-drying to keep you warm even if you get wet. Active underwear is available in several different weights and fabrics for different activities. Lightweight underwear is used for aerobic winter sports and Midweight and Heavyweight underwear are utilized by more serious arctic travelers or less active people. There is even a windstopper fabric that you can wear without a shell which makes it ideal for runners, cyclists or skiers. Keep in mind, however, that cotton is not a suitable underwear fabric for outdoor use as it does not dry quickly which can lead to hypothermia.

Mid-Layer Pants
Your legs carry the load and take the greatest abuse while in the backcountry. Rugged leg protection is important. Pants must be constructed from tight-weaved, abrasion-resistant material that is heavily sewn and reinforced at wear points yet styled for movement and utility. Cold weather calls for fleece, wool, or synthetic pants with ‘warm when wet’ characteristics to prevent hypothermia. Backcountry pants should also be windproof and waterproof and breathable for snow or wet conditions.

Mid-Layer Tops
Synthetic fleece or wool blend tops are appropriate middle layers for active outdoor adventures. If you wear a shirt under your fleece or wool top, be sure that the shirt does not fit tightly so moisture next to your skin can vent outward. Air flow is very important. (Never wear cotton tops while active because it will trap moisture next to your skin.) There is a tremendous variety of fleece tops available in assorted weights and styles to fit your needs. Fleece is versatile, easy to care for, dries quickly and insulates even when wet. Wool acts many of the same ways as fleece in that it insulates even when wet and traps warm air next to your body for insulation. Either choice is a good one for keeping you warm and moving moisture away from the skin while being active outdoors in cold weather.

Insulation Layer
A layering system needs a midweight filled parka, fleece parka, goose down or fleece vest that is lightweight and can pack into a small stuff sack into your backpack. This layer is the one to pull out when you stop for lunch on a ski tour, cycle trip or hike. Vests work well for active people giving them greater arm mobility and more ventilation. The heat retention of the garment is determined by its loft (thickness) and how well the insulation resists heat loss. A goose down, fleece or fiber-filled garment will be your best insulation against the cold.

Goose down is the lightest insulator known to man. Goose down is highly compressible, resilient and gives great mobility. Quality synthetic fills also work very well and are non-allergenic. Heavyweight fleece is also non-allergenic and very effective with the added advantage of keeping you warm if it gets wet because it dries very quickly. Whether you choose parkas or vests, fleece or goose down, they will all work well as an insulating layer against cold weather.

Shell Outerwear
The outer shell of your winter attire is your first line of defense against the elements. Gore-Tex® or other waterproof/breathable fabrics are ideal for backcountry shell outerwear. They shed water and pass moisture away from your body to keep you warm and dry. Shell Outerwear for backcountry use must have the following 4 primary characteristics:

Be Waterproof.
Wetness is the greatest threat to your safety. Wet clothing loses heat significantly. It could be said that mastering the wilderness is the art of staying dry.
Block the wind.
Wind carries huge caches of heat away and can drop your body temperature down below desirable levels. Protection is needed to stay comfortable and warm.
Resist Abrasion.
There is nothing more damaging to clothing than a thorny thicket. If your safety relies on your shell, it must be tough and able to withstand abuse from the trail.
Fit and be easy to use.
In the most severe weather you will notice the difference between easy or not easy to use. It is then that you have mountain boots with gaiters, mittens, a down jacket, a wool hat and all the vents battened down. You will notice if your shell fits, if it shelters your face from the elements, is easy to unzip with your mittens on and if you are able to move around while wearing all of it tromping through the wilderness.

As well as the necessary characteristics mentioned previously, you want to look for other features that are useful in your backcountry shell outerwear. When looking for a backcountry shell parka, look for an integral hood with ample visor and a drawcord, draft and rain flaps over all zippers and pockets, ventilation gussets (especially at wrists), ample room for insulating layers, and pit zips to ventilate under your arms. When looking for backcountry shell pants, look for leg zippers with rain flaps for putting on over boots, a drawcord/elastic waist section and elastic at the ankles. These features will give you that added extra comfort and mobility when you hit the trail.

Winter Accessories
When suiting up for the outdoors, you can not neglect the accessories that will keep your head, hands and feet warm. Footwear, gloves or mittens and hats are key in keeping your extremities warm in the frigid winter months.

Foot Protection
Your socks should be wool or synthetic but never cotton. Socks must fit into your boots with some breathing room left over for air circulation. Always have a dry pair handy.

When choosing boots, fit comes first, durability second and waterproofness, third. The most high tech boot made is no good to you if it doesn’t fit your feet properly. Fortunately, we offer a wide selection from many manufacturers to make sure you can find the perfect fit. Good boots will fend off rocks, ankle bruises, water and will enhance your agility. Please see our “Feet First” brochure for more detailed boot information.

Lastly, Gaiters over your boots will keep snow, wetness and brambles off your legs and socks. In deep snow or brush, this is an accessory not to do without.

Hand Protection
The hands transmit heat rapidly and they are the first to get cold out in winter weather. Mittens are the warmest protection and are mandatory for arctic backcountry conditions. Gloves are suitable for most Mid-Atlantic winters, however liners under gloves or mittens are a must.

Head and Neck Protection
We radiate 30% of our body heat from our head. In cold conditions, a convertible balaclava is the most versatile and easy to use. Convertible balaclavas can be worn as full head and neck protection, head protection only or neck protection only. Synthetic facemasks and helmet liners (balaclava) also provide exceptional warmth and keep the head dry. Keeping your head, neck and face dry and warm is very important for your health and overall body temperature regulation in severe cold weather.

Prevent Thermal Illness
The body works best with an internal temperature of 98.6ÞF and a skin temperature of 91.4ÞF. Body core temperature variations of only a few degrees too high or low can cause serious thermal illness, possible permanent injury and even death.

Hyperthermia
In high temperatures with high humidity the body has difficulty losing heat. It can sweat out up to two quarts of water per hour trying to do so. Prolonged muscular exertion (which produces more heat) can raise the core temperature resulting in hyperthermia. Symptoms are exhaustion, heat stroke or cramps.

To prevent hyperthermia: Drink plenty of water (special drinks like Gatorade also help replace body salts), dress in loose fitting, light colored hydrophobic clothing with a wide brimmed hat for shade and do not over-exert yourself. Make sure to take rests in the shade.

Hypothermia
Below 60ÞF air temperature or 70ÞF water temperature, the unprotected body loses heat quite rapidly. The colder the conditions, the less the body is able to produce heat. When heat is lost faster than it can be replaced, hypothermia results. This is a lowering of the body core temperature past the point of recovery. Symptoms are loss of coordination, disorientation, stupor and violent shivering. Minor shivering is a pre-hypothermia condition.

To prevent hypothermia: Conserve body heat by wearing proper insulation and layering for your activity level. Hats, gloves and dry footwear are especially important. Stay dry by controlling sweat build-up through layering wicking fibers, venting your clothing and wearing proper raingear. Heat loss through evaporation and conduction to water is dramatic. Finally, prevent dehydration by drinking lots of warm fluids. Do not drink alcohol or smoke as these activities will hasten hypothermia.

Please speak to our staff for any questions you may have about the proper attire for any outdoor adventure. A great experience begins by keeping safe and warm.

**DRJJ** · February 4, 2007, 10:50 PM

Re: PREVENTING INDOOR HYPOTHERMIA

It's been a long time since I have owned wool clothes and down bags (SoCal resident) but, if I remember correctly, wet wool will only keep you warm down to 45 degrees Farenheit, it takes forever to dry out and it is very heavy.

Down is even worse. If it gets damp, it looses all of it insolating capacity. The moisture from sleeping in a small tent over night will significantly dampen a down bag. If it is sunny or dry, the bag can easily be dried during the day. If, however, it is raining or damp or foggy, a down bag warmth may be seriously comprised. The feathers all stick together and are hard to get dry and get fluffed up again.

So use caution. A judicious mix of wool, down and synthectics may be prudent. I am a huge fan of polar plus and gortex. Polar Plus will dry in 1/20th (guessimate) the time of down or wool. I love naturnal fabrics, but not for staying warm.

**Jonesie** · February 11, 2007, 04:13 AM

Re: PREVENTING INDOOR HYPOTHERMIA

Monday, 27 December, 1999, 13:35 GMT

Feeling the chill

Mountaineers face the threat of hypothermia

The damage caused to the body by even a few degrees of chill can be life-threatening - but advances in medical techniques make hypothermia a 'surviveable' condition.

The human body is finely tuned to work at almost exactly 37 degrees centigrade, and normally a combination of staying out of the worst weather, and wrapping up warm can keep it that way.

But people caught out in the open, or drenched in water can cause core temperature to drop rapidly.

Doctors define hypothermia as having a body temperature below 35 degrees, but even then, the person might not feel unwell.

Instead, the signs to look out for are erratic behaviour, and even exaggerated confidence or recklessness.

Dr Jel Coward, a GP from Tywyn in North Wales, and an expert in wilderness medicine, says: "The mental process start to slow down and the person will start to behave quite strangely."

At first, the patient will have the body's natural shivering response, designed to warm the body up, but as hypothermia increases, this will stop.

At this stage, getting a person to warmth and shelter may be enough to reverse the decline.

However, once unconsciousness sets in, and the body temperature drops much lower, attention by doctors in a hospital equipped to re-warm the patient are needed.

No pulse

An extremely cold person will , once unconscious, almost reach a state of suspended animation, with the heart rate slowing down to almost inperceptible levels - it can be hard to find a pulse on a severely hypothermic patient.

Most first aiders' initial response to a patient appearing to lack a heartbeat would be to start 'cardiac massage'.

However, research has shown that the heart rhythms of severely hypothermic patients are extremely fragile, and the sudden shock could push them into 'fibrillation', which would stop pumping and lead to death if resuscitation is stopped for any reason.

Hypothermia can kill avalanche victims

Dr Coward says: "You would have to keep resuscitating the person all the way to hospital - and if you're on a cold hillside hours away from that, it could be difficult or even impossible to do this."

Instead, some experts recommend that the adult patient is wrapped up, and taken straight to hospital without resuscitation being attempted.

The lengths of time that the human body can survive in these circumstances are remarkable.

In one case, the "shutdown" of the body was so complete that a Canadian child lived after spending 40 minutes submerged in a frozen lake.

Most experts recommend that resuscitation is carried out on children found unconscious.

Hospital techniques

Once hospital is reached, the delicate process of re-warming can begin.

One method is to pass warm water through the spaces between the organs in the abdominal cavity - in one side, and out the other.

Another, more commonly-used technique is to hook up the victim to a bypass machine, which takes blood from the body, warms it up, then puts it back in.

Dr Coward says: "It's important that anyone with severe hypothermia is taken to hospital. While mild hypothermics may respond to a warm log cabin, more serious cases will not."

He said that attempts to warm up severe cases could be counterproductive.

When the body shuts down, the blood virtually stagnates in the extremities, and cells release potassium into it.

If this blood is warmed and returned to the core, the potassium can harm the heart.

BBC News | HEALTH | Feeling the chill

http://news.bbc.co.uk/1/hi/health/576784.stm

BBC, News, BBC News, news online, world, uk, international, foreign, british, online, service

**Amish Country** · February 18, 2008, 06:50 PM

Re: PREVENTING INDOOR HYPOTHERMIA

This is a link to an article from Mother Earth News entitled: "How the Japanese Keep Warm" and it describes some ingenious traditional methods of keeping warm. I do not know how addaptable they would be in our westren culture. There are some fire safety and ventalation issues that would also have to be addressed.

Page not found –

http://www.motherearthnews.com/Green-Homes/1976-01-01/Oriental-Heat-Retention-Homes.aspx

Mother Earth News has a lot of information on many topics including: off grid living and urban and rural homesteading.

Below is an additional link of similar information.

Keeping Warm in Japan - Everything2.com

http://everything2.com/index.pl?node_id=633657

It is summer now and hot so, perversely, I thought I’d mention a few ways of keeping warm. Traditional Japanese heating methods have always sought to he...

The following link provides more pictures to better illustrate the items being discussed.

http://www.amie.or.jp/daruma/Hibachi.html

**Sunshine123** · March 13, 2008, 07:48 PM

Re: PREVENTING INDOOR HYPOTHERMIA

Some college kids as a prank, wall papered the whole apartment with foil. Covered the ceiling, walls, cabinets, doors and windows with foil. The news crew got so warm while filming the story they had to strip down to their shorts. The foiled apartment (sorry for the pun) acted as a parabolic dish. I keep a large roll of foil (Costco) and staples (stapler) for my safe room should I have to fall back to emergency mode with no heat and/or fuel.

**tropical** · March 14, 2008, 08:48 AM

Re: PREVENTING INDOOR HYPOTHERMIA

"I keep a large roll of foil (Costco) and staples (stapler) for my safe room should I have to fall back to emergency mode with no heat and/or fuel."

Don't forget a source of oxigen ...

**Sunshine123** · April 6, 2008, 09:44 PM

Re: PREVENTING INDOOR HYPOTHERMIA

MY ABILITY TO SEAL THE ROOM AS AIR TIGHT IS OVERSTATING MY CARPENTRY ABILITY. BUT I WILL KEEP BEAN SPROUTS JUST IN CASE.........

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