Encyclopedia / F / Frostbite


What Is Frostbite?

Frostbite is the freezing of skin and damage to underlying blood vessels upon exposure to extreme cold. Blood flow halts in frostbitten skin, and the area must be thawed and rewarmed swiftly to prevent tissue death (gangrene) and infection. The ears, nose, hands, and feet are especially susceptible. Frostbite is sometimes accompanied by a life-threatening drop in internal body temperature, known as hypothermia, which must be treated first. Less severe forms of frostbite are referred to as frostnip and chilblain.

Who Gets Frostbite?

Anyone can get frostbite, which occurs from exposure to cold weather. Temperature, length of exposure, and the extent to which a person is protected against the cold determine whether—and how quickly—frostbite occurs.


Frostbite can be insidious—if you’ve been out the cold for awhile and your skin and extremities feel numb, you may not notice it has set in. Once it has set in, symptoms can progress from mild to serious.

  • In mild frostbite, a stinging or burning sensation is felt, accompanied by redness and swelling—and then numbness.
  • As frostbite becomes more severe, the skin may appear white and waxy and feel hard on the surface.
  • Deep frostbite is characterized by skin that is bluish gray and feels very hard and numb.
  • Blisters and bruising may appear upon rewarming.

Causes/Risk Factors

  • Exposure to extremely cold temperatures (32°F or below) for prolonged periods of time causes frostbite. The risk becomes greater as the temperature drops and the wind increases. Frostbite occurs more quickly at higher altitudes.
  • Wet clothing and skin increase the risk of frostbite.
  • Certain conditions, such as diabetes mellitus, poor circulation, or previous frostbite predispose a person to frostbite.
  • Fatigue and dehydration increase the risk of frostbite, as do alcohol and drugs.

What If You Do Nothing?

If you not get out of the cold, mild frostbite will progress—to the point where medical attention is required to avoid severe damage to the skin.


  • Presence of symptoms points toward frostbite.
  • Mild frostbite (without blisters or numbness) may be treated at home. If there is any question as to the severity of frostbite, go immediately to an emergency room for evaluation.


  • Go inside as soon as possible. Do not rub snow on the affected area.
  • Remove clothing from frostbitten skin and cover the affected area with warm blankets. Do not rub or massage the affected area.
  • Do not attempt to warm the area using hot air or an open flame.
  • Warm, not hot, water (100°F to 108°F) may be used to thaw the affected area. The water should feel comfortably warm, but not hot, to undamaged skin. It is important not to allow the affected area to refreeze.
  • If the frostbite is severe, do not attempt to thaw the area or administer first aid. Wrap the frozen area in a blanket or other soft material to protect it and go directly to an emergency room.
  • Ibuprofen or other over-the-counter pain relievers should be taken immediately to ease pain during thawing.
  • Your doctor may prescribe painkillers to relieve severe pain, and antibiotics to prevent damaged tissue from becoming infected. A tetanus shot should also be given.
  • In severe cases, surgery may be necessary to remove damaged tissue. It may take several weeks to determine the full extent of the damage. Rarely, amputation is necessary.
  • .If possible, avoid walking on frostbitten feet or toes to avoid causing further injury.


  • Wear several layers of warm, protective clothing when you go out in cold weather. Clothing should be dry and should not be restrictive. Mittens are preferable to gloves and protection of the head and ears is important.
  • Do not allow yourself to become overly tired, dehydrated, or hungry.
  • Avoid smoking or drinking before venturing out into extreme cold. Tobacco decreases circulation by constricting blood vessels, and alcohol increases heat loss and impairs judgment.

When To Call Your Doctor

Emergency:  Call an ambulance or go to an emergency room if you are concerned that frostbite may be severe.

Robert Hurd, M.D., American Board of Internal Medicine and Professor of Endocrinology and Health Care Ethics, Xavier University, Cincinnati, OH. Review provided by VeriMed Healthcare Network.