Cold-related injuries, such as hypothermia and frostbite, occur when low temperatures damage the body. In cases of hypothermia, the body's internal temperature falls, causing blood flow and breathing to become dangerously slow. In cases of frostbite, outer parts of the body, such as fingers and toes, start to freeze. Other cold-related injuries include chilblains and trench foot.
Anyone who spends time outdoors in cold weather can be at risk for cold-related injuries. That includes people who fish, hunt, or hike, especially in the mountains, where temperatures can drop quickly, and icy rain or snow can blow in with little warning. In snowstorms, people trapped in their cars can suffer permanent injury or even death if they cannot keep warm until help arrives.
In cities, homeless people who remain outdoors in the cold are at special risk. Likewise, poor people who cannot afford to heat their homes or whose landlords do not provide heat face dangers from the cold.
Indoors or outdoors, elderly people, the very young, and those who abuse alcohol or drugs also are at extra risk. Hypothermia, in which body temperature falls, is most common in cold, wet weather. In some cases, however, people who are elderly or who have diabetes, hypothyroidism, or other underlying diseases can become hypothermic while indoors even if the heating is adequate. In these cases, hypothermia may develop gradually over days. With elderly people, in particular, it can occur at temperatures as high as 65° F (18° C). This situation develops because aging can reduce the body's ability to conserve heat and to maintain an internal (core) temperature of about 98.6° F (37° C). In addition, elderly people may not feel the cold as much, so they may not take steps to get warm.
In the United States, 1,500 people die each year from hypothermia, but doctors suspect that thousands of elderly people may be hospitalized for problems caused by undiagnosed hypothermia.
Frostbite is the freezing of any part of the body. Ice crystals form within or between the cells. Red blood cells and platelets *
In dealing with frostbite, doctors usually recommend that the affected body parts be warmed rapidly in warm, but not hot, water. Doctors warn against rubbing the frostbitten parts by hand or with snow because this action can cause more tissue damage.
The affected part begins to become pink or red when it is thawing. If it remains white, the body part requires more time to thaw adequately.
After the rapid thawing, small blisters will appear. They will break in about a week, and a black scab will form after the blisters rupture. Normal tissue may have already formed below. Treatment at this point typically involves protecting the thawed part to avoid both refreezing and excessive heat. Usually, medical professionals advise that the area be cleaned with mild soap, but they do not suggest that either bandages or dressings be used.
Doctors recommend exercises to preserve joint motion in hands and feet. In some cases, a patient may require early surgical removal of the dead tissue to save the entire part from amputation. If necessary, medical professionals may also prescribe antibiotics.
Hypothermia (hy-po-THER-mee-a) is the lowering of the body temperature below 95° F (35° C). This condition usually results from prolonged exposure to cold when the body heat loss is greater than heat production. In some people, including the elderly and those with certain underlying diseases, hypothermia can occur even indoors and at temperatures that would otherwise be sufficient. Hypothermia can be life threatening. As in cases of frostbite, the sooner a person with hypothermia receives treatment, the better the chances for survival.
Some symptoms of hypothermia are slurred or incoherent speech, irritability, slowed rate of breathing, and a drop in awareness. Another common symptom is violent shivering, which is the body's response to cold as it attempts to warm itself. Without treatment, a person may become exhausted and stop shivering, which leads to an even more rapid decline in body temperature. Children and the elderly are particularly susceptible to hypothermia because their body temperature lowers especially quickly.
Treatment for hypothermia includes keeping the patient warm while seeking immediate medical attention. If the clothing is wet, it should be removed carefully. The patient should be warmed slowly, starting with the trunk of the body (not the extremities) by covering with warm blankets. If the person is unconscious and not breathing, someone who has been trained in cardiopulmonary resuscitation (CPR) should use this revival technique. Provide warm fluids (but not coffee or alcohol).
Trench foot is a painful disorder of the foot involving damage to the skin, nerves, and muscle that is caused by prolonged exposure to cold or dampness or by prolonged immersion in cold water. World War I soldiers fighting in the trenches developed this painful condition because they did not have access to clean, dry socks and boots.
One of the best ways to prevent cold-related injuries is to dress properly in cold, damp weather. Doing so requires wearing several layers of dry, loose-fitting clothing that allow perspiration to evaporate, and keeping gloves and socks dry. People in the cold should also protect exposed flesh from the wind. Face masks, hoods, and ear muffs are helpful. Hats are important because up to 40 percent of the body's heat is lost through the head. In addition, consuming adequate amounts of food and fluid helps the body to generate heat.
Another important prevention rule is to listen to highway department advisories about driving during snowstorms, because getting caught in a stalled car in a snowstorm can easily lead to frostbite and hypothermia. Safety supplies to carry along on a car trip during severe cold weather include a small shovel and rock salt, a blanket, high-energy foods such as granola bars, and a coffee can with some candles and matches. A lighted candle propped inside a large can provides a good source of heat.
See also Gangrene • Heat-Related Injuries
American Academy of Orthopaedic Surgeons (AAOS). Wilderness First Aid: Emergency Care In Remote Locations. Burlington, MA: Jones and Bartlett, 2013.
Hubbard, James. Living Ready Pocket Manual—First Aid: Fundamentals for Survival. Iola, WI: Living Ready Pocket Manual, 2013.
Kappes, Bruno, William Mills, and James O'Malley. “Psychological and Psychophysiological Factors in Prevention and Treatment of Cold Injuries.” Alaska Medicine. 35, no. 1. Also available online at http://hosting.uaa.alaska.edu/afbmk/media/samplepublications/Psy_and_PsySoc_Factors_in_Prevent.PDF (accessed November 29, 2015).
International Mountain Bicycling Association. “Winter Cold Injuries.” IMBA.com . https://www.imba.com/resources/nmbp/winter-coldinjuries (accessed November 29, 2015).
Cleveland Clinic. 9500 Euclid Avenue, Cleveland, OH, 44195. Toll-free: 800-223-2273. Web site: http://my.clevelandclinic.org/healthy_living/sports/cold-related_injuries.aspx (accessed November 29, 2015).
Outdoor Action Program, Princeton University. 350 Alexander St., Princeton, NJ 08540. Telephone: 609-258-3552. Website: http://www.princeton.edu/~oa/safety/hypocold.shtml (accessed November 29, 2015).
* platelets (PLATE-lets) are tiny disk-shaped particles in the blood that play an important role in clotting.