Frostbite
What is it?
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 (see Hypothermia for more information). Less severe forms of frostbite are referred to as frostnip and chilblain.
What Causes It?
- 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.
- 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.
Prevention
- 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.
Diagnosis
- 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.
How to Treat It
- 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 war m 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. It is important not to allow the affected area to refreeze.
- If the frostbite is severe, do not attempt to thaw the area. Go directly to an emergency room.
- Ibuprofen or other over-the-counter pain relievers should be taken immediately to ease pain during thawing.
- Aloe Vera may be applied to the skin to ease pain and inflammation.
- 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.
When to Call a Doctor
- EMERGENCY Call an ambulance or go to an emergency room if you are concerned that frostbite may be severe.
For more Johns Hopkins health information, please visit Johns Hopkins Health Alerts.
For medical appointments at Johns Hopkins, please call 866-386-1617.
All information contained within the Johns Hopkins Symptoms and Remedies website is intended for educational purposes only. Consumers should never disregard medical advice or delay in seeking it because of something they may have read on this website.
Copyright © 2008 Medletter Associates, LLC
Content excerpted from Johns Hopkins Symptoms and Remedies: The Complete Home Medical Reference.