This winter has already seen deadly cold snaps where people have found themselves at the mercy of the elements. Whether it’s on a wilderness hike or stranded in a car on a snow-covered highway, the physical effects of exposure to cold (also called “hypothermia”) can be life-threatening.
Hypothermia is a condition in which body core temperature drops below the temperature necessary for normal body function and metabolism. Normally, the body core is between 97.5-99.5 degrees Fahrenheit (36.0-37.5 degrees Celsius). Cold-related illness occurs once the core temperature dips below 95 degrees (35 degrees Celsius).
When it is exposed to cold, the body kicks into action to produce heat. Muscles shiver to produce heat, and this will be the first symptom you’re likely to see. As hypothermia worsens, more symptoms will become apparent if the patient is not warmed.
Aside from shivering, the most noticeable symptoms of hypothermia will be related to mental status. The person may appear confused, uncoordinated, and lethargic. As the condition worsens, speech may become slurred; the patient will appear apathetic, uninterested in helping themselves, and may lose consciousness. These effects occur due to the effect of cooling temperatures on the brain: The colder the body core gets, the slower the brain works. Brain function is supposed to cease at about 68 degrees Fahrenheit, although there have been exceptional cases where people (usually children) survived even lower temperatures.
Prevention of Hypothermia
An ounce of prevention is worth a pound of cure. To prevent hypothermia, you must anticipate the climate that you will be traveling through; include windy and wet weather into your calculations. Condition yourself physically to be fit for the challenge. Travel with a partner if at all possible, and have more than enough food and water available for the entire trip.
It may be useful to remember the simple acronym C.O.L.D. This stands for: Cover, Overexertion, Layering, and Dry.
Cover. Your head has a significant surface area, so prevent heat loss by wearing a hat. Instead of using gloves to cover your hands, use mittens. Mittens are more helpful than gloves because they keep your fingers in contact with one another, conserving heat.
Overexertion. Avoid activities that cause you to sweat a lot. Cold weather causes you to lose body heat quickly; wet, sweaty clothing accelerates the process. Rest when necessary; use those rest periods to self-assess for cold-related changes. Pay careful attention to the status of the elderly and the very young. Diabetics are also at high risk.
Layering. Loose-fitting, lightweight clothing in layers trap pockets of warm air and do the best job of insulating you against the cold. Use tightly woven, water-repellent material for wind protection. Wool or silk inner layers hold body heat better than cotton does. Some synthetic materials, like Gore-Tex, work well also. Especially cover the head, neck, hands and feet.
Dry. Keep as dry as you can. Get out of wet clothing as soon as possible. It’s very easy for snow to get into gloves and boots, so pay particular attention to your hands and feet.
One cold-weather issue that most people don’t take into account is the use of alcohol. Alcohol may give you a “warm” feeling, but it actually causes your blood vessels to expand; this results in more rapid heat loss from the surface of your body.
Alcohol and recreational drugs also cause impaired judgment. Those under the influence might choose clothing that might not protect them in cold weather.
If you encounter a person who is unconscious, confused, or lethargic in cold weather, assume they are hypothermic until proven otherwise. Immediate action must be taken to reverse the ill effects of hypothermia. Important measures to take are:
Get the person out of the cold. Move them into a warm, dry area as soon as possible. If you’re unable to move the person out of the cold, be sure to place a barrier between them, the wind, and the cold ground.
Monitor breathing. A person with severe hypothermia may be unconscious. Verify that they are breathing and check for a pulse. Begin CPR if necessary.
Take off wet clothing. If the person is wearing wet clothing, remove gently. Cover the victim with layers of dry blankets, including the head, but leave the face clear.
Share body heat. To warm the person’s body, remove your clothing and lie next to the person, making skin-to-skin contact. Then cover both of your bodies with blankets. Some people may cringe at this controversial notion, but it’s important to remember that you are trying to save a life. Gentle massage or rubbing may be helpful. Avoid being too vigorous.
Give warm oral fluids if awake and alert. If, and only if, the affected person is alert and able to swallow, provide a warm, nonalcoholic, non-caffeinated beverage to help warm the body. Coffee’s out, but how about some warm apple cider?
Use warm, dry compresses. Use a first-aid warm compress (a fluid-filled bag that warms up when squeezed), or a makeshift compress of warm, not hot, water in a plastic bottle. Apply to the neck, armpit, and groin. Due to major blood vessels that run close to the skin in these areas, heat will more efficiently travel to the body core.
Avoid applying direct heat. Don’t use hot water, a heating pad or a heating lamp directly on the victim. The extreme heat can damage the skin, cause strain on the heart, or even lead to cardiac arrest.
Joe Alton, MD
Find out more about cold-related injuries in our Third Edition of the Survival Medicine Handbook, now at 700 pages! Also, fill those holes in your medical supplies at Nurse Amy’s store at store.doomandbloom.net. You’ll be glad you did.