What is frostbite?

Frostbite is a potentially permanent condition that happens when your body tissues (like fingers, toes, ears) are injured by exposure to cold weather or cold water. You’re more likely to get frostbite during winter, in windy weather and at high altitudes. Even though your exposed skin gets frostbitten first, it can still happen even if your skin is covered.

How cold does it have to be to get frostbite and how long does it take?

Single-digit Fahrenheit temperatures are cold enough to cause frostbite. It’s important to remember that the colder it is outside, the faster you can get symptoms. In fact, you can get frostbitten in just half an hour or less when the wind chill is -15F (-26 C) or lower.

How is frostbite different from hypothermia?

Hypothermia happens when your body temperature drops below 95° F (35° C). Your normal body temperature is about 98.6° F (37° C). Hypothermia is more serious and widespread in your body than frostbite, which affects specific parts of your exposed skin. Frostbite happens when part of your body freezes, damaging your skin cells and tissues. Just like ice coating your windshield, your skin becomes hard and white when frostbitten. You can get both hypothermia and frostbite at once, and both are medical emergencies.

Who is at risk for frostbite?

If you’ve got exposed skin in cold temperatures, you’re at risk of frostbite. You’re also at a higher risk of developing frostbite if you:

  • Take medicine for high blood pressure.
  • Have diabetes.
  • Smoke.
  • Have peripheral vascular disease, a serious condition involving blood vessels.
  • Have Raynaud’s phenomenon (Raynaud’s disease), a condition that involves periodic narrowing (or spasms) in the blood vessels.
  • Have poor circulation or dehydration.
  • Haven’t dressed appropriately for cold weather or high altitude (swimming, hiking or climbing).
  • Are an infant.
  • Are elderly.
  • Have a physical or mental condition that prevents you from protecting yourself against the cold (like fatigue, mental illness, heavy sweating).
  • Have been drinking alcohol or taking drugs.

What are the 3 stages of frostbite?

Frostbite begins with mild symptoms but quickly becomes a serious health risk the longer your skin freezes from exposure. There are three stages of frostbite, including:

  • Frostnip: During frostnip, if you notice symptoms at all, you may see that the affected skin is red or a pale white. The skin may also feel cold, numb or tingly. Frostnip is the warning stage when skin damage is still just temporary. So if you notice symptoms, get inside immediately and treat the area with warm (never hot) water. Afterward you may get small red bumps (chilblains) on your skin.
  • Superficial (surface) frostbite: In the second stage, your skin might feel warm, but the water in your skin is slowly freezing into ice crystals. Your skin may also sting or swell up. After rewarming, you might see mottled patches or purple or blue areas that hurt or burn (just like a bruise). Your red skin might start to peel and hurt just like a sunburn — and you need to seek immediate medical treatment. You may also get fluid-filled blisters in the area after a day or so.
  • Severe (deep) frostbite: In the third stage, your lower layers of skin (subcutaneous tissue) freeze and total numbness in the area sets in. You may be unable to move the area that’s frostbitten or you may not be able to move it normally. Get medical attention immediately. Big blisters will appear on the frostbitten skin a day or two afterward. Finally, the frostbitten skin turns black as its cells die from freezing. This black skin might form a hard black covering (carapace) that falls off on its own — otherwise it will usually need to be removed surgically.

If you notice any of the symptoms of the second or third stages of frostbite, get immediate medical treatment to help prevent long-lasting damage.

What causes frostbite?

Frostbite happens when your skin is exposed to cold temperatures or cold water. It can also happen when you’re exposed to temperatures that aren’t quite as cold, but you’re exposed for a longer period of time. Ice packs and cold metal can cause frostbite if they’re pressed directly against your skin. You can even get frostbite through clothing, including your fingers when you’re wearing gloves.

During frostbite, the water in your skin freezes, causing visible and invisible damage to your cells and soft tissues. Frostbite usually affects your extremities (fingers, toes and ears) first. But it’s just as easy to get frostbitten on your cheeks and chin. The cold can injure both your skin and the tissues underneath — like muscles, nerves and joints.

What are the symptoms of frostbite?

Frostbite becomes more severe as your skin temperature drops or the longer your skin stays exposed. Frostbite symptoms include:

  • Numbness.
  • A painful feeling of “pins and needles” in the exposed area.
  • Hardening of your skin that’s been uncovered skin too long in the cold.
  • Redness (for mild frostbite).
  • Pale or waxy color and feel (for more severe frostbite).
  • Swelling.
  • Blisters (clear or blood-filled) or scabs.
  • Loss of coordination (stiff movements, falling down).
  • Pain when rewarming the affected area.

What does frostbite feel like?

Frostbite is so dangerous because it often numbs your skin first, so you may not feel that anything’s wrong at all. You might feel pain in your skin that’s exposed to the cold. Or your skin might feel suddenly hard or soft. Severe frostbite often causes your skin to swell up, and you might also get uncomfortable blisters. You may start feeling feverish or suddenly clumsy.

What are the complications of frostbite?

When frostbite continues past the first stage (frostnip), it can have long-term or permanent side effects. You might feel symptoms of nerve damage (neuropathy), like always feeling numb, sweating heavily or being more sensitive to cold. You’re also more likely to get frostbitten again once it’s happened. Frostbite arthritis — stiffness usually found in the hands and feet — can settle in your joints months or even years later.

Your skin itself might change color, or your fingernails might be damaged or lost. If the skin has turned black, you’re also at risk of getting gangrene (a condition where the skin rots) or becoming infected. Knowing how severe and long-lasting frostbite is can help you take steps to prevent it.

Last reviewed by a Cleveland Clinic medical professional on 05/21/2020.

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