When exposed to extreme cold temperature, the body tries to maintain core temperature by constricting blood vessels, resulting in reduced blood flow in areas farthest away from the center of the body. When this occurs in the fingers and toes, the diminished blood flow will increase the chance of injury from cold temperatures.
Factors that increase the risk of frostbite include the length of exposure to cold temperatures, alcohol use, peripheral vascular disease, peripheral neuropathy, direct contact with water or ice, and smoking.
Symptoms when exposed to the cold that may lead to frostbite include finger and toe numbness, pain in the fingers and toes, increasing redness in the fingers and toes, and the sense that the tissues feel frozen.
The injury sustained from frostbite may be described as superficial or deep based on the depth of soft tissue involvement. Superficial frostbite may appear as a white area of skin surrounded by redness, and with clear or cloudy blisters. The deeper frostbite may show bloody blisters or hard black areas of skin and result in soft tissue death. The chance for tissue recovery is better with the more superficial frostbite.
These images show deep frostbite at the fingertips.
Treatment for frostbite is tailored to the severity of the soft tissue injury and generally involves rewarming of the affected body part, wound care of any blistering or damaged tissue, and surgical management including amputation.
Reasonable precautions should be taken to minimize the risk of frostbite. Dress properly for the cold weather by protecting hands and feet along with the face and ears. Be aware of symptoms and check frequently. Avoid staying outside in wet clothes and prolonged exposure after alcohol consumption.
If there is concern that frostbite is occurring, one should get out of the cold to a warm location, remove any tight or wet clothing around the affected area, and seek medical treatment. If medical treatment is unavailable, consider placing the hands or feet in warm water and avoid things that may contribute to further damage such as hot water, rubbing the skin, and popping blisters.