Frostbite occurs when the skin and body tissue just underneath it freezes. Your skin becomes very cold, then numb, hard and pale. Frostbite typically affects smaller, more exposed areas of your body, such as your fingers, toes, nose, ears, cheeks and chin.
The first stage of frostbite irritates the skin but doesn't cause permanent damage. You can treat mild forms of frostbite with first-aid measures, including slowly warming your skin with warm water. Severe frostbite, however, requires medical attention, as it can damage skin, tissues, muscle and bones and lead to complications, such as infection and nerve damage.
Frostbite occurs when skin and underlying tissues freeze. The most common cause of frostbite is exposure to cold-weather conditions, but direct exposure to freezing materials, such as ice, also can cause frostbite.
Frostbite occurs in two ways:
- Losing body heat. Frostbite can occur in conjunction with hypothermia, a condition in which your body loses heat faster than it produces heat, causing dangerously low body temperature. When core body temperature lowers, it decreases circulation and threatens vital organs. This triggers a life over limb response, meaning your body protects vital organs, sometimes at the expense of extremities. With decreased circulation to the skin, your body temperature lowers and the tissue freezes.
- Direct contact. If you're in direct contact with something very cold, such as ice or metal, heat is conducted away from your body. Such exposure lowers the temperature of the skin and freezes the tissue.
Signs and symptoms of frostbite include:
- A slightly painful, prickly or itching sensation
- Red, white, pale or grayish-yellow skin
- Hard or waxy-looking skin
- A cold or burning feeling
- Clumsiness due to joint and muscle stiffness
- Blistering, in severe cases
Frostbite typically affects smaller, more exposed areas of the body, such as your fingers, toes, nose, ears, cheeks and chin. Because of area numbness, you may not realize you have frostbite until someone else points it out.
Frostbite occurs in several stages:
- Frostnip. A mild form of frostbite in which your skin turns red and feels very cold. Continued exposure leads to prickling and numbness in the affected area. As your skin warms, you may feel pain and tingling.
- Superficial frostbite. The second stage of frostbite appears as reddened skin that turns white or very pale. The skin may remain soft, but some ice crystals may form in the tissue. If you treat frostbite at this stage, the surface of your skin may appear mottled, blue or purple as it's warmed or thawed. With warming, you may notice stinging, burning and swelling. A fluid-filled blister may appear 24 to 36 hours after rewarming the skin.
- Severe or deep frostbite. As frostbite progresses, it affects all layers of the skin, including the tissues that lie below. You may experience deceptive numbness in which you lose all sensation of cold, pain or discomfort. Joints or muscles may no longer work. Large blisters form 24 to 48 hours after rewarming. Afterward, the area turns black and hard as the tissue dies.
Cold exposure that's severe enough to cause frostbite can also cause hypothermia. When your body temperature drops, your heart, nervous system and other organs don't work correctly. Left untreated, hypothermia eventually leads to complete failure of your heart and respiratory system and to death.
Gradually warming the affected skin is the key to treating frostbite. To do so:
- Protect your skin from further exposure
- Gradually warm frostbitten areas.
- Don't walk on frostbitten feet or toes if possible.
- If there's any chance the affected areas will freeze again, don't thaw them.
- Know what to expect as skin thaws. If the skin turns red and there's a tingling and burning sensation as it warms, circulation is returning. But if numbness or sustained pain remains during warming or if blisters develop, seek medical attention.
Limit your time outdoors in the cold, wet or windy weather and dress in several layers of warm clothing, wear a hat and cover your ears. Eating and drinking warm well-balanced meals and sweet drinks will help you stay warmer.