Diagnosis

Diagnosing frostbite is based on your signs and symptoms, skin appearance, and a review of recent activities in which you were exposed to cold.

Your doctor may order X-rays, a bone scan or an MRI to help determine the severity of the frostbite and check for bone or muscle damage.

Mayo Clinic Minute: Why the risk of frostbite is greater than you think

As winter drags on and temperatures drop way down, your risk of cold-related injury like frostbite can go way up.

"Literally think of it as freezing of the tissues," Dr. Sanj Kakar Mayo Clinic Orthopedic hand and wrist surgeon says frostbite is more common than many people think.

"We tend to see frostbite, for example, when the temperature is 5 degrees Fahrenheit with minimal windchill," Dr. Kakar explains.

If the windchill drops below negative 15 degrees Fahrenheit, not unheard of in the northern half of the U.S., frostbite can set in within half an hour.

The most vulnerable areas of frostbite are your nose, ears, fingers and toes.

"Initially [with] the milder forms, you can get some pain and some numbness of the tips, but the skin can change its color," Dr. Kakar says. "It can be red. It can be white. Or it can be blue. And you can get these blisters on your hands. And it can be a very serious injury."

The worst cases, the tissue can die, and you may need surgery to remove it.

So who's most at risk?

"[Those most at risk are] certain patients with diabetes, patients who have previous history of frostbite are prone to it, the elderly or your very young children, and also, for example, if you're dehydrated," he says.

More Information

Treatment

Mild frostbite (frostnip) can be treated at home with first-aid care. For all other frostbite, after appropriate first aid and assessment for hypothermia, medical treatment may involve rewarming, medications, wound care, surgery and various therapies, depending on the severity of the injury.

  • Rewarming of the skin. If the skin hasn't been rewarmed already, your doctor will rewarm the area using a warm-water bath for 15 to 30 minutes. The skin may turn soft. You may be encouraged to gently move the affected area as it rewarms.
  • Oral pain medicine. Because the rewarming process can be painful, your doctor will likely give you a drug to ease the pain.
  • Protecting the injury. Once the skin thaws, your doctor may loosely wrap the area with sterile sheets, towels or dressings to protect the skin. Or the doctor may protect your fingers or toes as they thaw by gently separating them from each other. And you may need to elevate the affected area to reduce swelling.
  • Removal of damaged tissue (debridement). To heal properly, frostbitten skin needs to be free of damaged, dead or infected tissue. To better distinguish between healthy and dead tissue, your doctor may wait 1 to 3 months before removing damaged tissue.
  • Whirlpool therapy or physical therapy. Soaking in a whirlpool bath (hydrotherapy) can aid healing by keeping skin clean and naturally removing dead tissue. You may be encouraged to gently move the affected area.
  • Infection-fighting drugs. If the skin or blisters appear infected, your doctor may prescribe oral antibiotics.
  • Clot-busting drugs. You may receive an intravenous (IV) injection of a drug that helps restore blood flow (thrombolytic), such as tissue plasminogen activator (TPA). Studies of people with severe frostbite show that TPA lowers the risk of amputation. But these drugs can cause serious bleeding and are typically used only in the most serious situations and within 24 hours of exposure.
  • Wound care. A variety of wound care techniques may be used, depending on the extent of injury.
  • Surgery. People who have experienced severe frostbite may in time need surgery or amputation to remove dead or decaying tissue.
  • Hyperbaric oxygen therapy. Hyperbaric oxygen therapy involves breathing pure oxygen in a pressurized room. Some patients show improved symptoms after this therapy. But more study is needed.

Lifestyle and home remedies

To care for your skin after frostbite:

  • Take all medications — antibiotics or pain medicine — as prescribed by your doctor. For milder cases of frostbite, a nonprescription pain reliever can help reduce pain and inflammation.
  • For superficial frostbite that has been rewarmed, some people find it soothing to apply aloe vera gel or lotion to the affected area several times a day.
  • Get out of the cold and wind. Don't thaw or warm the affected area if it might refreeze. Remove wet clothes once you're indoors. Seek emergency medical care.
  • Remove rings or other tight items. Try to do this before the affected area swells.
  • Don't walk on frostbitten feet, if possible
  • Don't apply direct heat or rub the area.
  • Don't break blisters that may develop. Blisters act like a bandage. Allow blisters to break on their own.

Preparing for your appointment

Call your doctor if you suspect you have frostbite or hypothermia. Depending on the severity of your symptoms, you may be told to go to an emergency room.

If you have time before your appointment, use the information below to get ready for your medical evaluation.

What you can do

  • List any signs and symptoms you've been experiencing and for how long. It will help your doctor to have as many details as possible about your cold exposure and to know if your signs and symptoms have changed or progressed.
  • List your key medical information, including any other conditions with which you've been diagnosed. Also list all medications you're taking, including nonprescription medications and supplements.
  • Make a note of the date of your last tetanus shot. Frostbite increases the risk of tetanus. If you haven't been vaccinated or if your last shot was more than 10 years ago, your doctor may recommend that you be vaccinated.
  • List questions to ask your doctor. Being prepared will help you make the most of the time you have with your doctor.

For frostbite, some basic questions to ask your doctor include:

  • Are tests needed to confirm the diagnosis?
  • What are my treatment options and the pros and cons for each?
  • What results can I expect?
  • What skin care routines do you recommend while the frostbite heals?
  • What kind of follow-up, if any, should I expect?
  • What changes in my skin should I look for?

Don't hesitate to ask any other questions that occur to you.

April 27, 2022
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