Hypothermia 101: Diagnosis, Treatment, and Prevention

Managing your body temperature with layers goes
a long way when it comes to hypothermia prevention.

When it comes to staying safe while enjoying your favorite activities in cold weather, preparedness
and knowledge are some of the best tools you can take with you on your adventures. Aside from having the right gear and knowing how to use it, knowing how to prevent, diagnose, and treat basic ailments you're more likely to face in cooler temperatures can be a life-saver.

While planning a cold weather backpacking trip, I got to chatting with my partner in crime, who happens to be a paramedic, about one of the most common cold weather-related injuries - hypothermia.

Spending a day hiking on a windy, exposed ridge in the snow? Sweating through your layers when it's chilly out without a dry set to change into? Accidentally falling in a creek midway through an overnight backpacking trip in the winter? You're at risk.

Before you head outdoors in the cold, make sure you know what someone who's hypothermic looks like, the ailment's cause, and how to prevent anyone in your party from being afflicted with it.

Causes of Hypothermia

Essentially, you become hypothermic if your body loses heat faster than it can produce heat.  Any time you're in an environment where you're exposed to cold temperatures, cold water, or really, any temperature colder than your body temperature in the right conditions, hypothermia is a possibility. Exposed skin and direct contact with something cold like snow, ice, or water can contribute to body heat loss. Another culprit is wind; combined with wet conditions, wind can rapidly drain your body of heat even if it's not freezing outside. Certain factors can increase your risk of hypothermia, including age, alcohol or drug use, certain medical conditions, and medications you're taking.

Diagnosing Hypothermia

Though it's tough to measure your body temperature in the field, there are a variety of signs and symptoms to be on the lookout for when you're outdoors. Frozen body tissue, as my paramedic partner in crime says, is "really, really bad news." Allowing tissue to reach a freezing temperature can result in permanent damage. But there's a lot that can happen to your body between a normal body temperature (37ºC) and frozen tissue (0ºC), and it's important to know the signs of various stages of hypothermia.

Know what hypothermia looks and feels like before you head out.

If the body temperature drops into the 34-35ºC, that's mild hypothermia. The brain still works and it'll start activating autonomic responses to fight the cold, like full body shivering and increased production of hormones like epinephrine (adrenaline). Drop into the 33-34ºC range and the victim might start breathing more rapidly, feel dizzy and/or nauseous, and experiencing compromised mental functions like trouble speaking and slight confusion.

Moderate and severe hypothermia are significantly more dangerous. If the body temperature drops into the 30-33ºC range, the victim will exhibit further compromised cognition and coordination functions. Speech may be slow and slurred. The victim's hands won't work like they should. They might appear confused and make odd decisions, like trying to remove clothing.

At this stage, self-protective mechanisms will stop working, i.e. the victim might stop shivering. To protect vital organs, blood will be shunted toward their core. Their fingers, nose, ears, and lips may appear pale, ashy, gray, even blue. They may not have the coordination and cognition needed to adequately help themselves and might show lack of concern about their condition. At this stage, you've got a medical emergency on your hands.

If the victim's body temperature drops below 30ºC, cardiac output is reduced, they'll respond less to light and other stimulants, and they run the risk of brain death. The majority of people with body temperatures at 27ºC or below are comatose. Their heart rate and breathing slow down so much that it can become challenging to tell if the victim is still alive. They may also go into spontaneous cardiac arrest.

Treating Hypothermia Outdoors

So, what happens if someone in your group starts experiencing some of these symptoms, even symptoms of mild hypothermia? If untreated, hypothermia is a true medical emergency. Seek immediate medical attention for anyone who appears to have hypothermia and get them into an environment where symptoms can be treated as quickly as possible. If the victim is severely hyopthermic, they can't be warmed up effectively without professional help. They need to be in a hospital.

But if help is far away, there are some things you can do until help arrives. Get the victim to a warm place if possible, moving them as gently as you can. Avoid jarring movements, including rubbing or massaging the victim. If the victim's clothing is wet, remove it and replace it with dry clothing. Cover the victim with warm, dry blankets, leaving the face exposed, and keep them insulated from the ground. If you have a sleeping bag handy, getting into the sleeping bag with them to share body heat is an option. Warm liquids free of alcohol and caffeine can be given to the victim by mouth if they're awake and able to drink.

If necessary, medical professionals might use techniques like blood rewarming or warm IV fluids to treat the victim once they're in a hospital.

Preventing Hypothermia

Staying fueled and hydrated always helps!

Of course, the best way to deal with hypothermia is to avoid getting it in the first place. Make sure
you know the signs and symptoms, and how to recognize them. Know that feeling cold and shivering is a warning sign to start taking aggressive action to get yourself or whomever in your party is showing symptoms warm. Once you begin having altered mental status, you're less likely to be able to recognize that you have a problem and less able to do something about it.

Also, a prolonged fight to stay warm, even if you're winning, consumes a lot of energy. You'll need to keep adding fuel to the furnace in the form of carbs. If your glycogen stores become depleted, your temperature will drop more easily. And as much fun as enjoying your favorite alcoholic beverage outdoors can be, note that drinking can come with increased risk of hypothermia.

Remember, the thermal conductivity of water is about 30 times that of air. Translation? You'll get colder a lot faster if you're wet, so don't get wet. That includes sweating while you're playing outside in the cold. Avoid overheating, wear layers, keep your extremities covered, and keep your clothing dry. Know that you'll lose more heat from your extremities, which as far as your body is concerned, are expendable when you're fighting to keep vital organs from freezing. Blood gets shunted away from your extremities to your core where the important stuff, like organs, live. Then we start getting concerned about frostbite/nip.

This article isn't an exhaustive list of all things related to hypothermia, nor is it a substitute for medical training, but hopefully it's a good place to start for anyone with an interest in playing outside in the cold! Have you or anyone you know been affected by hypothermia? What else would you add in terms of diagnosis, treatment, and prevention tips? We'd love to hear from you in the comments!

Sources: The Mayo Clinic, Diseases and Conditions, Hypothermia, Medscape, and Daniel Herscovitch, NRP.