• Hypothermia
  • Frostbite
  • Trench Foot (Immersion Foot)
  • Other Cold Injuries


    Hypothermia is the loss of core body temperature as a result of exposure to cold temperatures, wind and/or water. It is a life-threatening condition that requires immediate action to stabilize the victim and rewarm the body. Once shivering begins, death can result in as little as 90 minutes.

    It is therefore critical to identify and treat hypothermia in the initial stages, when the body temperature has begun to drop below 98 F. Look for violent shivering, slurred speech, mild confusion, signs of depression, impairment of motor skills, and a sluggish, stumbling walk. If these symptoms are present, move the victim to a warm area. Contrary to the old folk remedy, do not give the victim whiskey. It may bring a feeling of warmth, but alcohol dilates blood vessels, causing further heat loss. Instead, give the victim warm, sugary liquids and dry clothing. Cover the head to shorten the warming time. For more pronounced cases, cover all the extremities—arms, legs, hands, feet and head—to retain heat. Watch for any continued loss of motor skills or coherency, and seek medical attention if conditions worsen.

    If the body temperature lowers to below 90 degrees F, the hypothermia has become severe. The degradation in coordination and motor skills intensifies, shivering stops and the mind becomes affected, showing signs of confusion and irrationality. As the temperature drops further, sleepiness becomes more dominant, heartbeat and respiration slows and the skin feels extremely cold to the touch. Below 82 F, unconsciousness sets in, followed by respiratory and heart failure.

    A victim in this condition is near death. Cut away wet or frozen clothing and apply warm compresses, hot water bottles or warm rocks to the neck, armpits and groin. Do not warm the extremities—this may cause cold blood to flow to the core, further lowering the core temperature. Wrap the victim with multiple layers—sleeping bags, warm blankets, clothing, etc. Administer warm sugar water, and help the victim urinate. Emergency evacuation should be the priority before any additional rewarming is attempted. CPR may be needed and should be started at any onset of respiratory or cardiac failure.

    If the victim has fallen into cold water, he or she must be pulled out immediately and put into dry clothes. Water conducts heat away from the body many times faster than air.


    Frostbite is the freezing of body tissue, resulting in the loss of feeling and skin color, redness, pain, blistering, and in advanced cases, gangrene.

    Frostbite damages tissue in three ways. First, ice crystals form in the tissue, killing tissue cells. Second, extreme cold causes blood vessels to constrict and blood to clot, depriving tissue cells of the oxygen they need to survive. Third, inflammatory chemicals are released, causing further blood vessel constriction, blood clotting and tissue death.

    Frostbite can occur anywhere on the body, but the most frequently affected areas are the toes, fingers, ears and nose. The three stages of frostbite are frostnip, superficial frostbite and deep frostbite.

    Frostbite is preceded by a cold response where the affected skin becomes red and painfully cold. Continued exposure leads to frostnip, a freezing of the top layers of skin. Frostnip is often not recognized by the victim, as it has very subtle symptoms such as tingling and slight whitening of the skin color. After thawing, the affected area may become red and painful, and later peel like a sunburn.

    With superficial frostbite the skin feels frozen and waxy and numbness occurs. In this stage, ice crystals form deeper inside the skin, but do not affect the underlying tissue. After thawing, blisters usually appear.

    With deep frostbite the affected areas feel completely numb and wooden. Deep frostbite is very dangerous, as it can lead to blood clotting and extensive tissue death. If gangrene sets in, amputation of the affected area is likely.

    Treatment for frostbite consists of quickly warming the affected part or area. Frostnip is easily treated by blowing on the area with warm breath or immersion into warm water. Placing the affected part in contact with or within warmer areas of the body, such as against one's chest or in one's armpit, is also very effective for frostnip. Treatment for superficial frostbite is similar, except the thawing time is longer.

    If deep frostbite occurs, ideally the person should be evacuated for medical treatment. Rewarming of the area should be started immediately. If water is available, immersion in 104- to 108-degree F water (about the temperature of hot tap water) will warm the area and eliminate the ice crystals within the tissue. Make sure the tissue is completely thawed. If water is not available, cover the area in a manner that will allow it to warm, but only if you are sure it will not freeze again, which will cause additional damage.

    When rewarming the affected area, remember that the skin has no feeling; placing the affected areas next to the fire, or in water that is too hot, can result in burns. Do not rub the affected area, as this will cause more damage. Additionally, do not let the victim use alcohol or tobacco. Alcohol dilates the blood vessels, which may increase fluid buildup. Tobacco constricts the blood vessels, decreasing the flow of blood to the outside of the body. Take ibuprofen to decrease pain and tissue damage.

    Trench Foot (Immersion Foot)

    Trench foot is a condition caused by prolonged exposure to wet and cold, which constricts blood vessels and may result in nerve and muscle damage from lack of oxygen and nutrients.

    Trench foot becomes worse the longer the foot is exposed to wet and cold. Initially, the foot may be cold to the touch, slightly swollen and mottled, numb and tender to the touch. If the foot continues to be exposed to wet and cold, swelling and a tingling pain develop. When rewarmed, the foot becomes red, dry and painful; blisters may develop. Over a period of weeks or months the swelling subsides and the foot may develop increased perspiration and sensitivity to cold, as well as itching. In less severe cases, the pain will subside within hours or days. In severe cases, gangrene may set in.

    If trench foot appears to be setting in, remove the foot from the wet environment. Wash and dry the foot, elevate it and warm it with your hands, but don’t rub it. Administer ibuprofen to ease pain and reduce swelling. If the victim develops blisters, professional medical attention is necessary.

    Other Cold Injuries

    Chilblains—Chilblains are a condition related to trench foot. When skin is kept cool and moist for an extended period, rewarming causes a rush of blood to the capillaries near the skin’s surface. The capillaries leak fluid into the surrounding tissue, resulting in swollen, red, itchy lesions that may fill with pus in severe cases. First aid includes keeping the skin warm and try and applying a protective ointment.

    Frozen Lung—Frozen lung is severe bronchial irritation that results from rapidly inhaling air faster than the airway can warm it. Symptoms include spasms in the muscles of the airway, a burning sensation, wheezing and sometimes coughing up blood. The victim should get out of the cold, rest, breathe warm and humidified air, and drink plenty of fluids.

    Snow Blindness—Snow blindness is sunburn of the eyes. Snow blindness is not actually caused by the cold, but by reflection of sunlight off snow or ice into the eyes. Symptoms include itchy, burning, red eyes, sensitivity to light, headache, excessive tearing, halos around light sources, and temporary loss of vision. The victim should get indoors in a dark room and apply a cold compress; a pain reliever may be taken. Do not rub the eyes. The condition will usually clear up in 18 hours. To prevent snow blindness, always wear sunglasses or snow goggles.