Although it may not be actively snowing and you may start venturing outdoors, remember that cold weather can affect your body in different ways. A previous blog post discussed hypothermia (abnormally low body temperature) because your body can lose heat faster than you can produce it. Because hypothermia happens gradually and affects your thinking, and can cause you to be sleepy, confused, and clumsy, you may not realize you need help. A body temperature below 95° F is a medical emergency and can lead to death if not treated promptly.
This article will focus on the dangers of frostbite. Frostbite is an injury to the body that is caused by freezing, resulting in a loss of feeling and color in affected areas. It most often affects the nose, ears, cheeks, chin, fingers, or toes — those areas farthest away from the heart. The classifications and signs/symptoms for tissue damage caused by extreme cold includes: frostnip, a superficial cooling of tissues without cellular destruction; at onset, there is itching and pain, and then the skin develops white, red, and yellow patches and becomes numb. Chilblains are superficial ulcers of the skin that occur when a predisposed individual is repeatedly exposed to cold; blisters may occur 1–2 days after becoming frozen. The blisters may become hard and blackened, most of them heal in one month, but the area may become permanently insensitive to both heat and cold. Frostbite involves tissue destruction. At or below 0 °C (32 °F), blood vessels close to the skin start to constrict, and blood is shunted away from the extremities. The same response may also be a result of exposure to high winds. This constriction helps to preserve core body temperature. In extreme cold, or when the body is exposed to cold for long periods, this protective strategy can reduce blood flow in some areas of the body to dangerously low levels. This lack of blood leads to the eventual freezing and death of skin tissue in the affected areas. The muscles, tendons, blood vessels, and nerves can freeze. The skin is hard, feels waxy, and use of the area is lost temporarily, and in severe cases, permanently. Frostbite can result in areas of purplish blisters which turn black and which are generally blood-filled. Nerve damage in the area can result in a loss of feeling. Extreme frostbite may result in fingers and toes being amputated if the area becomes infected with gangrene. The extent of the damage done to the area by the freezing process of the frostbite may take several months to assess, and this often delays surgery to remove the dead tissue.
The risk of frostbite is increased in people with reduced blood circulation, such as those with PAD (peripheral arterial disease), poorly controlled diabetes, peripheral neuropathy, Raynaud’s disease. At great risk are people who are not dressed properly for extremely cold temperatures; especially if you use a light jacket or no hat/mittens, because you are just running to the store for a short time, going out to eat, or not going far from home.
This information does not take the place of medical advice; consult emergency medical personnel, or your physician, immediately, if you have hypothermia or frostbite . For frostbite, general guidelines may include getting into a warm room as soon as possible; unless absolutely necessary, do not walk on frostbitten feet or toes—this increases the damage. Warm the affected area using body heat, such as the heat of an armpit can be used to warm frostbitten fingers. Do not rub the frostbitten area with snow or shake/massage it at all, this can cause more damage, especially if ice crystals have formed in the tissue. Don’t use a heating pad, heat lamp, or the heat of a stove, fireplace, or radiator for warming. Affected areas are numb and can be easily burned (especially when diabetes is not well controlled which can lead to decreased circulation and decreased sensation).
To help prevent frostbite, dress warmly and stay dry. Adults and children should wear a hat; a scarf or knit mask to cover face and mouth; sleeves that are snug at the wrist; mittens (they are warmer than gloves); water-resistant coat and boots; and several layers of loose-fitting clothing. Be sure the outer layer of your clothing is tightly woven, preferably wind resistant, to reduce body-heat loss caused by wind. Wool, silk, or polypropylene inner layers of clothing will hold more body heat than cotton. Stay dry—wet clothing chills the body rapidly. Excess perspiration will increase heat loss, so remove extra layers of clothing whenever you feel too warm. Also, avoid getting gasoline or alcohol on your skin while de-icing and fueling your car or using a snow blower. These materials in contact with the skin greatly increase heat loss from the body. Do not ignore shivering; it’s an important first sign that the body is losing heat; persistent shivering is a signal to return indoors. Be cautious about travel: listen for media reports of travel advisories issued by the National Weather Service; don’t travel in low visibility conditions, on ice-covered roads, overpasses, and bridges if at all possible. If you must travel by car, tire chains may help, and take a mobile phone with you. Let someone know your destination and when you expect to arrive; ask them to notify authorities if you are late. Check and restock the winter emergency supplies in your car before you leave. Never pour water on your windshield to remove ice or snow; shattering may occur. Don’t rely on a vehicle to provide sufficient heat; it may break down, or your battery may die if it’s more than 3 years old. Always carry additional warm clothing appropriate for the winter conditions. Staying in your vehicle when stranded is often the safest choice if winter storms create poor visibility or if roadways are ice covered. These steps will increase your safety when stranded. Tie a brightly colored cloth to the antenna as a signal to rescuers; move anything you need from the trunk into the passenger area; wrap your entire body, including your head, in extra clothing, blankets, or newspapers; stay awake so you will be less vulnerable to cold-related health problems. Run the motor (and heater) for about 10 minutes per hour, opening one window slightly to let in air. Make sure that snow is not blocking the exhaust pipe—this will reduce the risk of carbon monoxide poisoning. As you sit, keep moving your arms and legs to improve your circulation and stay warmer. Do not eat unmelted snow because it will lower your body temperature. Huddle with other people for warmth.
Check on your family members and neighbors frequently during winter weather emergencies. In the St Louis area, those with low incomes, senior citizens, and those with disabilities, may qualify for assistance with heating bills provided by heatupstlouis.org; 314-241-7668. For help in locating heated shelters, call the United Way, dial 211 via a telephone land line. Contact your local Government Centers (blue pages of the phone book) or Community Centers in your specific location.
Sources of this information: CDC: Centers for Disease Control and Prevention; 800-CDC-INFO; (800-232-4636; TTY: (888) 232-6348; www.cdc.gov. Mayo Clinic: www.mayoclinic.com. National Institute on Aging Information Center; 1-800-222-2225 (toll-free); 1-800-222-4225 (toll-free/TTY; www.nia.nih.gov.