Definition

Frostbite is damage to skin and tissues from prolonged exposure to below-freezing temperatures. Frostbite severity is based on the depth of tissue injury. The most severe frostbite can lead to permanent damage and/or amputation.

The most common parts of the body to become frostbitten include your fingers, toes, ears, nose, chin, or cheeks.

Frostbitten Skin Copyright © Nucleus Medical Media, Inc.

Causes

Exposure to below-freezing temperatures can cause the body tissue to freeze. Ice crystals form within the frozen body part. Blood cannot flow through the frozen tissue. This causes the frozen tissue to be deprived of blood and oxygen. The combination of freezing and oxygen deprivation causes tissue damage or tissue death. Some tissue damage may also happen during warming.

Risk Factors

Factors that may increase your chance of frostbite include:

• Exposure to below-freezing temperatures without adequate covering
• Low body temperature— hypothermia
• Being very young or very old
• Homelessness
• Fatigue
• History of previous cold weather injury
• High-altitude cold exposure
• Working in below-freezing conditions
• Participating in winter sports or high-altitude sports
• Wearing wet clothing
• Suffering from a condition that affects your mental status such as:
  • Head injury
  • Mental illness
  • Use of mind-altering drugs or alcohol
• Inability to move
• Using drugs that cause your blood vessels to become constricted
• Medical conditions, such as:
  • Malnutrition
  • Thyroid problems
  • Infection
  • Disease of the blood vessels
  • Arthritis
  • Diabetes
  • Raynaud phenomenon

Symptoms

Early stages of frostbite may cause:

• Weakness or clumsiness with extremities, such as with your hands or feet
• Numbness, stinging, burning, or tingling sensation
• Areas of white skin blended with or next to healthy-looking skin
• Coldness or firmness of tissue
• Pain, especially during the thawing process
• Inflammation may occur during the thawing process

Later stages of frostbite may cause:

• Waxy appearance of the skin
• Color ranging from white to blue, depending on severity
• Blisters that may be filled with clear or bloody fluid, usually during rewarming

Diagnosis

You will be asked about your symptoms and medical history. A physical exam will be done. Diagnosis is usually based on symptoms and the findings of the physical exam.

Treatment

Rapid rewarming in a warm (98.6 °F [degrees Farenheit (F)] to 102.2 °F / 37 °C [degrees Cesius (C)] to 39 °C) water bath is the treatment of choice. Slow rewarming may cause more tissue damage.

If you are stranded with frostbite and unable to get medical help:

• Try to get to a warm location. Wrap yourself in blankets.
• Do not put snow or hot water on the injured area.
• Do not rub affected areas.
• Tuck your hands into your armpits to try to rewarm them.
• If it's available, use warm water (at about 100 °F / 38 °C) to rewarm your frostbitten area.
• Avoid refreezing the affected area. This can result in more severe injury.
• Walking on frozen feet and toes can cause damage. It may be more important to find shelter.
• Drink warm liquids.
• Avoid alcohol and sedatives.
• Cover the injured area with a clean cloth until you can get medical help.
• Rewarming can be intensely painful. To relieve pain, take an over-the-counter pain medication such as acetaminophen or ibuprofen.

Prevention

To help reduce the chance of frostbite:

• Dress properly when going outside in cold weather:
  • Cover your head, face, hands, and feet adequately.
  • Wear layers of clothing.
  • Wear materials that provide good insulation, such as wool, polyester, or polypropylene. It should keep moisture away from the skin.
  • Wear a waterproof outer layer and stay dry.
• Avoid drinking alcohol when you will be in cold weather.
• Stay hydrated by drinking water.
• Recognize signs of early frostbite, such as numbness, paleness, and difficulty grasping objects with your hands.
• Treat early frostbite promptly with the body heat of a companion by using their abdomen or armpit for warmth.