Written by Marsha Seidelman, M.D.
January 28, 2014
What better time to talk about frostbite prevention than during a week of record low temperatures across the country?
Frostbite is the formation of tiny crystals inside the body which damage the cells and the blood vessels. Tiny blood clots form, so when the tissue is thawed, there is not enough blood flow, resulting in swelling in some areas, and destruction of tissue in others. Even when the air temperature is above the freezing mark, frostbite can occur from the wind chill factor making it cold enough for these changes to occur internally. The colder it is, the shorter time it takes for frostbite to occur – it can happen within minutes when the temperature is below zero. The most vulnerable parts are those with less blood flow or not covered from the cold. More blood flows to your core than to your skin or extremities, so the most likely body parts to be affected are your toes, nose, ears, cheeks, chin and fingers. Pay extra attention to covering these areas when going out in extreme cold. There is an even further increased risk of frostbite when blood flow to the extremities is impaired, as it is with poor heart function, diabetes, dehydration, or drug, alcohol or nicotine use. Also, use of certain heart medicines like beta blockers (propanolol, atenolol, carvedilol and others), or migraine medicines can restrict peripheral blood flow. Children are more susceptible to frostbite because they have more surface area of skin relative to their core and lose heat more easily. Even when they argue about wearing hats, gloves, scarves and boots, they must wear them – just be sure they don’t restrict blood flow by being too tight.
Staying active outside does help increase blood flow to the extremities, but these areas should still be protected from the cold. According to the CDC, loose fitting layered clothing, particularly wool or silk for the inside layer and wind and water-resistant material on the outside is ideal to protect from cold and moisture. Avoid wearing metal jewelry as these can make the skin even colder.
What does frostbite look like? With more superficial injuries, you can have swelling, redness, sometimes white or grey skin, or blisters. Deeper injuries can affect muscle and bone and may seem more waxy, yellow or violaceous. These deeper injuries increase the risk of subsequent amputation. At the first sign of skin turning red or white or feeling firm, waxy or clumsy, get out of the cold. If you notice these changes on someone else, bring it to their attention. Because of the numbness, they may not be aware of it.
To rewarm an area at risk stay in a warm room and use warm – NOT hot – water to soak. Be sure to test the water with someone’s non-frostbitten hand or elbow to assure that the water is not too hot. Do not rub the area or walk on affected toes, if possible. Yes, putting your frozen hand in your armpit constitutes an acceptable warming method. Don’t rewarm the area if it might get frozen again. Refreezing can cause even more damage. DO NOT use a heating pad, radiator or fireplace as the affected areas are easily burned. DO seek medical help for further advice.
Hypothermia is another cold-related hazard, but differs from frostbite. It occurs when the overall body temperature is below 95. At this point, the brain can be affected, making it even more difficult to get out of danger. We often hear about this in the elderly, babies, or homeless or athletic people who are outside for extended periods, especially in wet or restrictive clothing, or in those who have been drinking alcohol. Signs include shivering, confusion and fatigue. Get the person dry and warm by using blankets, a warm room and warm fluids by mouth if they are awake. Seek medical help immediately!
Hopefully before long, we can be talking about the dangers of extreme heat — but for now, stay warm and safe.
REFERENCES:
http://emergency.cdc.gov/disasters/winter/staysafe/frostbite.asp
Tags: frostbite, hypothermia