Cold Weather Cold Weather InjuriesInjuries

Cold Weather InjuriesCold Weather Injuries

Cold weather can lower body temperature, Cold weather can lower body temperature, resulting in impaired performance and cold resulting in impaired performance and cold injuries. When body heat loss exceeds the injuries. When body heat loss exceeds the body's ability to produce and retain heat, body's ability to produce and retain heat, body temperature decreases. When body body temperature decreases. When body temperature falls below 95°F (35°C), temperature falls below 95°F (35°C), hypothermia, a life-threatening condition, hypothermia, a life-threatening condition, follows. follows.

To reduce heat loss, the body decreases To reduce heat loss, the body decreases blood flow to the arms, legs, and skin. blood flow to the arms, legs, and skin. Although this protects the internal Although this protects the internal organs, the decreased blood flow organs, the decreased blood flow increases susceptibility of hands, feet, increases susceptibility of hands, feet, ears, etc. to non-freezing (trench foot) ears, etc. to non-freezing (trench foot) and freezing (frostbite) cold injuries. and freezing (frostbite) cold injuries.

Problems with Cold Problems with Cold EnvironmentsEnvironments

Cold stress Cold stress

Cold weather is often accompanied by wind, Cold weather is often accompanied by wind, rain, snow, and ice, which can worsen the rain, snow, and ice, which can worsen the effects of cold. For any given air temperature, effects of cold. For any given air temperature, the potential for body-heat loss, skin cooling, the potential for body-heat loss, skin cooling, and decreased body temperature is increased and decreased body temperature is increased by wind and moisture. Soldiers protect by wind and moisture. Soldiers protect themselves from cold weather by using clothing themselves from cold weather by using clothing and shelter. When this protection is inadequate, and shelter. When this protection is inadequate, the body has defense mechanisms to help the body has defense mechanisms to help maintain the correct temperature.maintain the correct temperature.

The body protects vital internal organs The body protects vital internal organs (brain, heart) by reducing skin blood flow (brain, heart) by reducing skin blood flow and increasing shivering. When the and increasing shivering. When the soldier notices these responses, it is a soldier notices these responses, it is a signal that clothing and shelter are signal that clothing and shelter are inadequate. Heat production is increased inadequate. Heat production is increased by shivering and increased physical by shivering and increased physical activity. The more vigorous the physical activity. The more vigorous the physical activity, the greater the heat production. activity, the greater the heat production.

However, high intensity physical activity However, high intensity physical activity can cause sweating, which may increase can cause sweating, which may increase the risk of cold injury if clothes become the risk of cold injury if clothes become wet. Also, inactivity for long periods wet. Also, inactivity for long periods increases the risk of cold injury. This is a increases the risk of cold injury. This is a particular concern for defensive fighting particular concern for defensive fighting positions (foxholes) or small vehicle crew positions (foxholes) or small vehicle crew compartments where movement is compartments where movement is restricted.restricted.

Because cold-weather clothing is heavy and cumbersome, it increases the energy required for physical activity. The increased effort can result in overheating and sweating, especially during hard work, and can contribute to increased fatigue. Heavy work and sweating leads to dehydration, which increases susceptibility to cold injury.

In addition, poorly conditioned soldiers are In addition, poorly conditioned soldiers are more susceptible to cold injury. They tire more susceptible to cold injury. They tire more quickly and are unable to stay active more quickly and are unable to stay active to keep warm. Lean soldiers are also more to keep warm. Lean soldiers are also more susceptible to cold injury because they susceptible to cold injury because they lack body fat, which is good insulation lack body fat, which is good insulation against cold. Illness, poor nutrition, and against cold. Illness, poor nutrition, and injury limit a soldier's ability to protect injury limit a soldier's ability to protect against cold injury.against cold injury.

AlcoholAlcohol

Alcohol increases susceptibility to cold Alcohol increases susceptibility to cold injury by increasing heat loss and reducing injury by increasing heat loss and reducing shivering.shivering. Alcohol increases urine output, which Alcohol increases urine output, which may lead to dehydration. Alcohol also blunts the may lead to dehydration. Alcohol also blunts the senses and impairs judgment, so the individual senses and impairs judgment, so the individual may not feel the signs and symptoms of may not feel the signs and symptoms of developing cold injury. In addition, any source of developing cold injury. In addition, any source of nicotine, such as smoking or chewing tobacco, nicotine, such as smoking or chewing tobacco, can increase susceptibility to cold injury.can increase susceptibility to cold injury.

Metal objects and liquid fuels Metal objects and liquid fuels

Metal objects and liquid fuels left in the Metal objects and liquid fuels left in the cold can pose a serious hazard. Fuels and cold can pose a serious hazard. Fuels and solvents remain liquid at very low solvents remain liquid at very low temperatures. Skin contact with fuel or temperatures. Skin contact with fuel or metal at below freezing temperatures can metal at below freezing temperatures can result in nearly instantaneous freezing result in nearly instantaneous freezing injury.injury.

Air temperature / ElevationAir temperature / Elevation

Air temperature decreases about 3.6Air temperature decreases about 3.6°°FF

(2.0°C) with every 1000 ft (300 m) increase in (2.0°C) with every 1000 ft (300 m) increase in elevation. Winds are usually more severe at high elevation. Winds are usually more severe at high altitude and there is less cover above the tree altitude and there is less cover above the tree line. Soldiers are more susceptible to frostbite line. Soldiers are more susceptible to frostbite and other cold injuries above 8000 ft (2400 m) and other cold injuries above 8000 ft (2400 m) than at sea level, due to the lower temperatures, than at sea level, due to the lower temperatures, higher winds, and lack of oxygen.higher winds, and lack of oxygen.

Cold InjuriesCold Injuries

Soldiers operating in cold environments Soldiers operating in cold environments are at risk for cold injuries that may reduce are at risk for cold injuries that may reduce unit readiness. These include: chilblain, unit readiness. These include: chilblain, trench foot, frostnip, frostbite, and trench foot, frostnip, frostbite, and hypothermia.hypothermia.

ChilblainChilblain

ChilblainChilblain is a nonfreezing cold injury is a nonfreezing cold injury which, although painful, causes little or no which, although painful, causes little or no permanent impairment. It appears as permanent impairment. It appears as tender, red, swollen skin that is hot to the tender, red, swollen skin that is hot to the touch and may itch. This can worsen to an touch and may itch. This can worsen to an aching, prickly ("pins and needles") aching, prickly ("pins and needles") sensation and then numbness. It may sensation and then numbness. It may develop in only a few hours in skin develop in only a few hours in skin exposed to cold.exposed to cold.

ChilblainChilblain

Immersion foot / Trench footImmersion foot / Trench foot Immersion foot / Trench foot Immersion foot / Trench foot develops when develops when feet are exposed to moisture and cold for feet are exposed to moisture and cold for prolonged periods (12 hours or longer). The prolonged periods (12 hours or longer). The combination of cold and moisture softens skin, combination of cold and moisture softens skin, causing tissue loss and, often, infection. causing tissue loss and, often, infection. Untreated, trench foot can eventually require Untreated, trench foot can eventually require amputation. Often, the first sign of trench foot is amputation. Often, the first sign of trench foot is itching, numbness, or tingling pain. Later the feet itching, numbness, or tingling pain. Later the feet may appear swollen, and the skin faintly red, may appear swollen, and the skin faintly red, blue, or black. Commonly, trench foot shows a blue, or black. Commonly, trench foot shows a distinct "water-line" coinciding with the water distinct "water-line" coinciding with the water level in the boot.level in the boot.

FrostnipFrostnip

FrostnipFrostnip involves freezing of water on the involves freezing of water on the skin surface. The skin will become skin surface. The skin will become reddened and possibly swollen. Although reddened and possibly swollen. Although painful, there is usually no further damage painful, there is usually no further damage after re-warming. Repeated frostnip can after re-warming. Repeated frostnip can dry the skin, causing it to crack and be dry the skin, causing it to crack and be sensitive. Frostnip should be taken sensitive. Frostnip should be taken seriously since it may be the first sign of seriously since it may be the first sign of impending frostbite.impending frostbite.

FrostbiteFrostbite

FrostbiteFrostbite involves freezing of deeper involves freezing of deeper layers of tissue. Ice crystal formation and layers of tissue. Ice crystal formation and lack of blood flow cause tissue damage. lack of blood flow cause tissue damage. Skin freezes at about 28°F (2.2°C). The Skin freezes at about 28°F (2.2°C). The skin becomes numb and turns a grey or skin becomes numb and turns a grey or waxy-white color, is cold to the touch, and waxy-white color, is cold to the touch, and may feel stiff.may feel stiff.

HypothermiaHypothermia

HypothermiaHypothermia: is a life-threatening condition in which : is a life-threatening condition in which body temperature falls below 95body temperature falls below 95°°F (35F (35°°C). Generally, C). Generally, body temperature will not fall until after many hours of body temperature will not fall until after many hours of exposure to cold air or shorter exposure to cold water. exposure to cold air or shorter exposure to cold water. Body temperature can fall even when air temperatures Body temperature can fall even when air temperatures are above freezing if conditions are windy, clothing is are above freezing if conditions are windy, clothing is wet, and/or the soldier is inactive. The first signs of wet, and/or the soldier is inactive. The first signs of developing hypothermia include confusion, bizarre developing hypothermia include confusion, bizarre behavior, and withdrawal from group interaction. Victims behavior, and withdrawal from group interaction. Victims of hypothermia may be unconscious, with nearly of hypothermia may be unconscious, with nearly undetectable breathing and pulse. undetectable breathing and pulse.

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Countermeasures for Problems Countermeasures for Problems in Cold Environmentsin Cold Environments

Conduct training for cold weather Conduct training for cold weather operations before deployment. Training operations before deployment. Training and education about cold weather hazards and education about cold weather hazards are essential because soldiers do not are essential because soldiers do not acclimatize very well to the cold.acclimatize very well to the cold.

Maintain physical fitness, since high levels Maintain physical fitness, since high levels of fitness are beneficial for participation in of fitness are beneficial for participation in cold-weather operations.cold-weather operations.

Minimize periods of inactivity in cold Minimize periods of inactivity in cold conditions.conditions.

Minimize risk of cold injuries in fighting Minimize risk of cold injuries in fighting positions and observation points by positions and observation points by placing pads, sleeping bags, etc. inside placing pads, sleeping bags, etc. inside these positionsthese positions. .

Maintain adequate food consumption to Maintain adequate food consumption to make up for increased energy make up for increased energy requirements in cold weather. Eat "normal" requirements in cold weather. Eat "normal" meals with frequent nutritious snacks from meals with frequent nutritious snacks from extra foods left over from mealtime.extra foods left over from mealtime.

Maintain proper hydration to reduce Maintain proper hydration to reduce susceptibility to cold injuries. Soldiers susceptibility to cold injuries. Soldiers participating in cold-weather operations participating in cold-weather operations should consume about a half a quart should consume about a half a quart (half a canteen) of water with breakfast, (half a canteen) of water with breakfast, lunch, dinner, and before going to sleep lunch, dinner, and before going to sleep at night. An additional half quart should at night. An additional half quart should be consumed every hour during the be consumed every hour during the workday (more if the work is strenuous workday (more if the work is strenuous enough to cause the individual to enough to cause the individual to sweat) for sweat) for a total of at least five to a total of at least five to six quarts per daysix quarts per day. .

Monitor hydration status by noting urine Monitor hydration status by noting urine color and frequency of urination. color and frequency of urination. Dark Dark yellow urine and infrequent urination yellow urine and infrequent urination indicate that fluid consumption should be indicate that fluid consumption should be increased.increased.

Avoid alcohol and tobacco because of their Avoid alcohol and tobacco because of their adverse effects in the cold.adverse effects in the cold.

Keep hands, feet, and skin dry. Change Keep hands, feet, and skin dry. Change socks whenever they become wet or socks whenever they become wet or sweaty. Wet socks can be air-dried and sweaty. Wet socks can be air-dried and carried under BDUs to warm them.carried under BDUs to warm them.

Keep clothing clean. Dirty clothing packs Keep clothing clean. Dirty clothing packs down, loses insulation value, and prevents down, loses insulation value, and prevents evaporation of sweat.evaporation of sweat.

Wear clothes in layers. Layered clothing Wear clothes in layers. Layered clothing allows soldiers to adjust to changes in allows soldiers to adjust to changes in temperature or physical workload. Wearing temperature or physical workload. Wearing layered clothing is especially important for layered clothing is especially important for soldiers whose duties require them to soldiers whose duties require them to move in and out of heated spaces, or to move in and out of heated spaces, or to periodically undertake vigorous physical periodically undertake vigorous physical activity.activity.

Wear clothes that allow air flow Wear clothes that allow air flow (ventilation) for evaporation of sweat. (ventilation) for evaporation of sweat. Physically active soldiers will sweat even Physically active soldiers will sweat even in extremely cold weather. If sweat does in extremely cold weather. If sweat does not evaporate, it will accumulate. Wet not evaporate, it will accumulate. Wet clothing loses its insulation value, clothing loses its insulation value, increasing the soldiers' risk of cold injury.increasing the soldiers' risk of cold injury.

The standard light-duty leather glove, The standard light-duty leather glove, worn with woolen inserts, provides inactive worn with woolen inserts, provides inactive persons with about 30 minutes of persons with about 30 minutes of protection from frostbite when air protection from frostbite when air temperature is 0temperature is 0°°F (17.8F (17.8°°C). If C). If temperatures are warmer and/or soldiers temperatures are warmer and/or soldiers are physically active, this glove will are physically active, this glove will provide effective protection for longer provide effective protection for longer periods. This glove is not waterproof.periods. This glove is not waterproof.

Trigger-finger or Extreme Cold Weather Trigger-finger or Extreme Cold Weather mittens with liners should provide additional mittens with liners should provide additional protection when air temperature is below protection when air temperature is below 00°°F (-17.8F (-17.8°°C), or more than 30 minutes of C), or more than 30 minutes of inactive exposure is anticipated.inactive exposure is anticipated.

Shake out sleeping bags before using to add Shake out sleeping bags before using to add air to the insulation (lofting), which will air to the insulation (lofting), which will improve insulation value. Use mats under improve insulation value. Use mats under the sleeping bag to prevent body heat loss. the sleeping bag to prevent body heat loss. Soldiers should keep their heads outside the Soldiers should keep their heads outside the sleeping bag, so that moisture from their sleeping bag, so that moisture from their breath will not accumulate in the bag. Air breath will not accumulate in the bag. Air out the sleeping bag as often as possible to out the sleeping bag as often as possible to evaporate moisture. evaporate moisture.

Sleep in long underwear and socks with Sleep in long underwear and socks with all other clothing hung up to dry when in all other clothing hung up to dry when in tents. In improvised shelters, only boots tents. In improvised shelters, only boots and the outermost clothing layer should and the outermost clothing layer should be removed for sleeping.be removed for sleeping.

Use lip balm to prevent chapped lips and Use lip balm to prevent chapped lips and sunburned lips (Cold Climate Lipstick, sunburned lips (Cold Climate Lipstick, Antichap, NSN 6508-01-277-2903). Skin Antichap, NSN 6508-01-277-2903). Skin moisturizing lotion may help the skin moisturizing lotion may help the skin retain water.retain water.

C-O-L-DC-O-L-D

WHEN USING COLD-WEATHER CLOTHING WHEN USING COLD-WEATHER CLOTHING

REMEMBER C-O-L-D: REMEMBER C-O-L-D:

keep it-------keep it-------CCleanlean avoid-------- avoid--------OOverheatingverheating wear it------- wear it-------LLoose in layersoose in layers keep it------- keep it-------DDryry

First Aid for Cold InjuriesFirst Aid for Cold Injuries

For For Chilblain and Trench footChilblain and Trench foot, prevent further cold , prevent further cold exposure. Remove wet or constrictive clothing. exposure. Remove wet or constrictive clothing. Gently wash, dry, and elevate the injured part. Cover Gently wash, dry, and elevate the injured part. Cover the injured area with layers of loose warm clothing the injured area with layers of loose warm clothing and allow to re-warm. Pain and blisters may develop. and allow to re-warm. Pain and blisters may develop. Do not pop blisters, do not apply lotions or creams, Do not pop blisters, do not apply lotions or creams, do not massage, do not expose to extreme heat, and do not massage, do not expose to extreme heat, and do not allow victim to walk on injury. Seek medical do not allow victim to walk on injury. Seek medical attention.attention.

For For FrostbiteFrostbite, prevent further cold exposure and , prevent further cold exposure and remove wet, constrictive clothing. Gradually re-warm remove wet, constrictive clothing. Gradually re-warm the injury by direct skin-to-skin contact between the injury by direct skin-to-skin contact between injured area and non-injured skin of victim or a injured area and non-injured skin of victim or a buddy. Evacuate for medical treatment. Victims with buddy. Evacuate for medical treatment. Victims with foot injuries should not walk, but should be evacuated foot injuries should not walk, but should be evacuated by litter. by litter. Do not thaw frostbite injuries if there is a Do not thaw frostbite injuries if there is a possibility of refreezing during evacuation.possibility of refreezing during evacuation.

For For HypothermiaHypothermia, prevent further cold , prevent further cold exposure and remove wet clothing. Initiate exposure and remove wet clothing. Initiate CPR if required. Re-warm by covering with CPR if required. Re-warm by covering with blankets, sleeping bags, and with body-to-blankets, sleeping bags, and with body-to-body contact. Handle gently during treatment body contact. Handle gently during treatment and evacuation because rough handling can and evacuation because rough handling can cause dangerous irregular heartbeats in cause dangerous irregular heartbeats in hypothermic victims.hypothermic victims.

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Questions?Questions?