frostbite (redirected from Congelatio)

frostbite (chilblains), injury to the tissue caused by exposure to cold, usually affecting the extremities of the body, such as the hands, feet, ears, or nose. Extreme cold causes the small blood vessels in the extremities to constrict. The blood circulates more slowly and stagnation results. Eventually the body fluids may freeze. The condition is aggravated by tight clothing, physical inactivity, and dampness. Severe frostbite that is not treated may result in gangrene; amputation of the affected part may be necessary. See first aid.

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frostbite

Freezing of living tissue, when it loses enough heat in below-freezing weather for ice to form. High winds, wet skin, tight clothes, and alcohol use increase the risk of frostbite. Cell damage, tissue dehydration, and oxygen depletion caused by freezing and thawing can lead to blood-cell disruption, clotting in capillaries, and gangrene. The toes, fingers, ears, and nose are usually affected first, becoming cold, hard, white, or bloodless. The lack of pain is dangerous. Core temperature should be brought to near normal before rapid thawing in warm (under 115 °F [46 °C]) water. Toxoid booster injections are recommended. The outlook is best when freezing is short-term, thawing is by rapid rewarming, and large blisters extending to the end of the part develop early. Tissue that is refrozen after thawing must almost always be amputated. Affected parts become more susceptible to recurrence. Frostbite is best prevented by wearing dry, layered, loose clothing and remaining alert. See also hypothermia.