Frostbite

Many of us live in or visit regions where winter are cold enough to bring the threat of frostbite. Frostbite occurs when skin and tissue freeze.

Causes

Frostbite can occur anytime skin is exposed to temperatures below about 28F. Wind and increasingly colder temperatures increase the risk. Hands, feet, nose, ears, and cheeks are the areas most commonly affected.

Symptoms

• Skin with frostnip, in which only the outermost layers of skin are frozen, may feel numb. It may also appear pale and waxy, and the surface of the skin may feel hard or rubbery but the tissues underneath are soft when depressed.

• With superficial frostbite, all layers of skin are frozen and the skin feels hard all the way through, not just on the top. A frostbitten area is cold, white or grayish-yellow, and hard to the touch. The area may feel very cold and numb, or there may be pain, tingling, or stinging. As the area thaws, it becomes red and painful. Blisters usually form within 24 hours after rewarming. See a health care provider as soon as possible.

• With deep frostbite, in which underlying tissue, blood vessels, nerves, muscles, and even bone are frozen, the tissue under the skin also will feel wooden, because it is frozen. Deep frostbite requires prompt medical care.

First Aid

• If you suspect frostnip or frostbite, get out of the cold immediately.

• Warm the affected area by putting the area next to another warm part of your body.

• Warm the affected area by putting it in barely warm, not hot, water (100F).

• Do not rub the frostbitten area. That can cause further injury to the frozen area.

• Do not use dry heat (such as a heating pad), and do not hold the area near a flame to rewarm. You can burn yourself, especially because you will not have full feeling in the frozen area to warn you when it is getting too hot.

• Drink warm liquids, such as tea, coffee, or hot chocolate.

• Get medical help immediately if the frostbitten area remains numb after you've tried to warm it.

• Do not rewarm a frostbitten area if there is a chance that it will freeze again before you can get to shelter and medical help. If you are in the wilderness or otherwise unable to get to help, keeping the frostbitten area frozen will not cause much additional harm. Further serious injury can occur if the area is warmed and then refrozen. Do cover the area, however, to protect it from freezing any deeper while you are trying to get to shelter and medical help.

• Do not pop blisters. Follow your doctor's treatment plan to prevent infection as the area heals.

• Protect previously frostbitten areas from exposure to cold. Tissue that has been damaged by frostbite will be more sensitive to frostbite in the future.

• Watch for signs of infection as the frostbitten area heals. These include pus or oozing, redness, an odor, or a red line moving away from the injured area.

• You may need a tetanus booster even if frostbite did not involve broken skin. Frostbite may cause skin to slough off later.

Preventive Care for Frostbite

• Pay attention to weather conditions and dress accordingly. Wear a hat or ear muffs, mittens, and a scarf.

• Avoid getting wet,  wet clothing looses most of its ability to insulate you against cold.

• Wear warm clothing.

• Use the "buddy system" -- don't go out alone in severe weather.

• Avoid alcohol and nicotine when you will be spending time out in the cold. Nicotine reduces blood circulation to the extremities -- your fingers, toes, nose, and ears. Alcohol speeds loss of heat from your body. In addition, alcohol can impair your judgement and you may not realize you are getting frostbite.

• Be alert to signs of frostnip and frostbite. Get out of the cold as soon as possible to prevent further injury.