Frostbite is an injury that results from overexposure of the skin to extreme cold. It occurs when ice crystals form in body tissues, and blood flow is restricted in the injured area. Frostbite most commonly affects the ears, nose, chin, fingers, and toes. The first sign of frostbite may be a light reddening of the skin. The skin color of the frostbitten area then becomes very pale or turns grayish-blue. Early symptoms include feelings of coldness, tingling, and pain. As frostbite progresses, the pain is replaced by numbness. A victim may not even be aware of the injury. When blood supply to the frostbitten area is lost, gangrene (tissue death) may develop (see Gangrene).
Frostbite should be cared for by restoring circulation and warmth to the affected area as quickly as possible. Do not rub the frostbitten area with snow or ice because rubbing might remove skin and damage tissue. Get the victim into a warm place and soak the frostbitten body parts in warm, but not hot, water. Loosely bandage the affected area. Place gauze or cloth between fingers or toes before bandaging them. Seek medical attention immediately.