MSU Extension

Hypothermia, or abnormally low body temperature, is a very dangerous condition that occurs when your body loses heat faster than it can produce it. For humans, normal body temperature can range from 97.7-99.5 degrees Fahrenheit with 98.6 F commonly considered average. However, when a person’s body temperature falls below 95 F, experts consider that a medical emergency. In the United States, each year over 1500 deaths are attributed to hypothermia.

Though hypothermia most often occurs in very cold winter weather, it can also happen when a person becomes chilled from rain or sweat in weather above 40 F. Additionally, hypothermia may result in people who are submerged in cold water because of a capsized boat or having fallen through ice on a river or lake.

According to the Centers for Disease Control and Prevention (CDC), warning signs for adults experiencing hypothermia include shivering, exhaustion, confusion, fumbling hands, memory loss, slurred speech and drowsiness. With infants, bright red, cold skin and very low energy are the primary symptoms. If medical care is not immediately available, you are advised to begin warming the person while waiting for first responders to arrive. Move them into a warm room or shelter, remove any wet clothing and warm them using blankets, concentrating at first on the trunk and head rather than extremities. If the person is conscious, providing warm non-alcoholic beverages will help increase their body temperature.

Those with severe hypothermia may be unconscious and seem to not have a pulse or be breathing. Cardiopulmonary resuscitation, commonly known as CPR, should be administered until medical assistance is available. The CDC notes cases in which individuals who initially appeared to be dead were successfully resuscitated.

The CDC reports those most at risk for hypothermia are people who are outdoors for long periods of time (the homeless, hikers, hunters, etc.), mentally ill individuals, adults under the influence of alcohol and elderly people with inadequate food, clothing or heating. As individuals age, metabolism slows and physical activity levels tend to drop which contributes to the increased risk in the elderly population.

Children left unattended and babies sleeping in very cold bedrooms are also at increased risk of becoming hypothermic. Because infants lose body heat more easily than adults and cannot make enough body heat by shivering, it is very important that the temperature of their room is between 68-72 F and they are dressed warmly.

Another concern during very cold weather is frostbite, an injury to the body caused when body tissues freeze. Frostbite most often affects fingers, toes and sensitive parts of the head including the nose, ears, cheeks, and chin. Initially it causes a loss of feeling and color but if severe enough can result in permanent damage to and even amputation of the affected body parts.

The first symptoms of frostbite include redness or pain in the area of skin exposed to very cold temperatures. The affected skin may be white or grayish-yellow in color and feel unusually firm or waxy. Body parts may become numb as the exposed tissues freeze making it even more difficult for the person to realize they are suffering frostbite.

As in the case with hypothermia, it is critical with frostbite to get the person into a warm room or shelter as soon as possible, Warm the affected area by immersing it in warm, not hot, water. Alternatively, you can utilize body heat as a means of warming. Placing frostbitten fingers in your armpit will quickly warm them. Do not walk on frostbitten feet or toes and do not massage frostbitten areas or rub them with snow as more tissue damage can result. Using a heating pad, heat lamp or stove, fireplace or radiator heat to warm affected areas is not recommended because burns may occur before being noticed due to numbness in those areas.

If you are stranded in a vehicle in cold weather, the CDC suggests you tie a brightly colored cloth to the outside of it as a signal to rescuers and stay in your vehicle. Even if you feel cold and uncomfortable while waiting in the vehicle, you are better protected against hypothermia and frostbite than if you attempted to walk to find help. If you have useful items in the trunk such as blankets and extra clothing, quickly move them into the passenger area and wrap your entire body including your head with them. It is important to stay awake, moving your arms and legs to keep warm and maintain circulation. Do not eat snow as it will lower your body temperature. Making sure the tail pipe is not blocked by snow and opening one window slightly to reduce the risk of carbon monoxide poisoning, run the motor with the heat on about ten minutes every hour.

What can you do to prevent hypothermia and frostbite from occurring in the first place? The CDC stresses the importance of wearing appropriate clothing for the weather conditions and outdoor activities you have planned. Wool, silk and synthetic fabrics such as polypropylene and polyester provide better insulation than cotton. Loose fitting clothes are best as tight clothing will reduce blood circulation. Cold weather gear should include a hat, a scarf or mask to cover your face, mittens rather than gloves, water-resistant footwear and jacket. Your body will stay warmer in extreme cold if you avoid alcohol and eat good, nutritious meals.

Visit the Michigan State University Extension website for more information about keeping safe and healthy during the winter months ahead.