Hypothermia develops when the body temperature falls below what is needed for proper bodily functions. When a part of the body, such as an arm, hand, foot, or leg, has tissue damage from being exposed to cold weather or water, this is called frostbite. Hypothermia and frostbite are medical emergencies. Frostbite can lead to gangrene and loss of the affected body part. It is important to prevent hypothermia and frostbite by taking precautions when the weather is cold.
Reddened skin that feels cool to the touch
Feeling “pins and needles” or numbness
Pain, often severe, during the rewarming process
Pale or waxy skin that feels cold or wooden
Numbness of the frostbitten area, which may persist even after rewarming
Black scabs (these often form after the injury itself)
Damage to the tissues under the frostbitten skin, including muscles, tendons, cartilage, joints, and bones
If hypothermia or frostbite is suspected (even a mild case), move the individual into a warm environment and away from wind. Once in a warmer environment, remove wet or damp clothes. Give the person something warm to drink if he or she is conscious. Never give alcoholic beverages or tobacco products to a person with hypothermia or frostbite. Remove jewelry from the area of frostbite. Do not rub, massage, or soak the frostbitten body part. Seek medical attention right away for suspected frostbite or for hypothermia, since you may not recognize how large an injured area is until after it has been rewarmed. Sterile, dry dressings can be applied to the frostbitten area to protect it while waiting for medical attention.
Limit your time outdoors when the weather is cold.
If you have to be outdoors, make sure you wear layers of warm and dry clothing. It is important to wear a hat because more than 20% of body heat is lost through the head. Also wear gloves, a hat or other clothing that covers the ears, and proper waterproof footwear. Remove wet clothing as soon as possible.
Protect children and older persons from cold temperatures. Make sure they have proper clothing if going outdoors or if in cold indoor environments.
When in the cold, do not use alcohol or other substances, since they can increase heat loss, in addition to making judgment poor.
Do not use tobacco products in cold environments because they can increase heat loss from the body and reduce circulation.
American College of Emergency Physicians www.emergencycareforyou.org
National Institutes of Health www.nih.gov
Arctic Health www.arctichealth.org
To find this and previous JAMA Patient Pages, go to the Patient Page Index on JAMA 's Web site at www.jama.com. Many are available in English and Spanish.
Sources: American College of Emergency Physicians, National Library of Medicine, National Institutes of Health, Arctic Health, University of Maryland Medical Center, Mayo Clinic
The JAMA Patient Page is a public service of JAMA. The information and recommendations appearing on this page are appropriate in most instances, but they are not a substitute for medical diagnosis. For specific information concerning your personal medical condition, JAMA suggests that you consult your physician. This page may be photocopied noncommercially by physicians and other health care professionals to share with patients. To purchase bulk reprints, call 312/464-0776.
Topic: EMERGENCY CARE
Torpy JM, Lynm C, Golub RM. Frostbite. JAMA. 2011;306(23):2633. doi:10.1001/jama.2011.1799