Outdoor safety is something that needs to be thought about and planned for. Most have and carry a good first-aid kit for most common injuries. But one potential condition often neglected in preparation activities no matter the season is hypothermia.

Recognizing hypothermia
“Hypo” means low, and “therm” means temperature or heat. In order to understand hypothermia you first need to understand how the body maintains its constant temperature of 98.6 degrees Fahrenheit. During situations when your body is cold, several mechanisms kick in to maintain your heart, lungs and stomach, and to keep these vital organs as warm as possible. Since most of us don’t routinely carry an internal thermometer, we must look for external signs of hypothermia.

With “mild” hypothermia (98.6 to 96 degrees in the body), these temperatures can vary from person to person. Blood to the extremities and skin will be restricted by the constriction of the blood vessels in these regions. Involuntary muscle contractions may start and a person may begin shivering. A person can walk and talk, but complex motor skills, like tying on a lure, can become difficult. Higher-reasoning skills can also be affected, including counting backward from 100 using 8-digit subtractions.

When the body temperature drops down to 96 or falls to 93, the “moderate” stage has been reached. Here, the body stops functioning properly and the “umbles” start: fumbling, mumbling, tumbling and grumbling. A person begins to drop things, cannot speak coherently, falls often and stops caring about his or her surroundings. One might begin nonsensical behaviors such as taking off clothing.

Once internal body temperatures fall below 92, shivering can become violent as the body uses up the last of its sugar. Here, muscles contract and a person may assume the fetal position. Also, pupils become dilated and the pulse drops. In one sense, the body is trying to go into “hibernation” by stopping all motion, reducing breathing and its heart rate.

Prevention
We think of hypothermia as a “winter-only problem,” but it can occur whenever air temperatures are below body temperatures. I modified an old mnemonic COLD and added an “H” for CHOLD: Cover, Hunger, Overexertion, Layers and Dry. This applies equally to warmer weather and colder conditions.

First, cover your head and hands, as these areas are where the largest amount of heat loss occurs, with some estimates at 25 percent lost from your head alone. We always think hats and gloves for winter, but they should be part of your warm-weather attire on days with below-average temperatures for that season. On the water, your PFD does more than keep you afloat if you take a spill; it can also maintain body heat.

Hunger includes not only food, but also water. Don’t wait to get hungry or thirsty and eat and drink often. When involved in all-day activities like fishing, the three-meals-a-day schedule doesn’t always work. You should nibble foods that are high in protein and complex carbohydrates like fruits and nuts. Foods high in sugar, i.e. candy, can give you a quick fix, but also a fast fall. Water is still the best form of hydration. Sport drinks have become popular, but these should not replace water as your primary source of hydration.

Overexertion and exhaustion can happen, even to people who are in great shape. Both your muscles and your mind need to adjust to different outdoor activities. Even if you workout at fancy gyms, you’re using different sets of muscles in different motions when hiking on non-flat terrain or when paddling on water. Ease into your outdoors trip and make your first day a short one. Sweating is good, but excessive sweating is not. Make sure you cover up when resting and when cooling the body down. A “push-it-to-the-limit” attitude is fine when you’re in a gym or backyard, but exhaustion is a killer when you are far from home and not in a controlled environment with many people. Twice—once on a canoe trip and once hiking—a partner and myself did well pushing it through the day and then experienced mild symptoms in camp.

Layering clothing applies in summer just as it does in winter, late fall and early spring. Plan for changes in weather (there are 40-degree says on July canoe trips in Canada), changes in elevation and changes in activity levels. Most of your outdoor clothing should be something other than cotton. There are a plethora of synthetic fabrics that dry faster and wick away moisture, retain more heat and pack smaller than cotton.

In the summer, getting wet is probably the leading cause of developing hypothermia. Water conducts away body heat 25 times better than air. Even 80-degree water is below the average body temperature, and enough to cause a substantial loss of heat. A summer shower, a fall into a creek, or tumbling out of a boat can all result in a soaking that can lead to hypothermia. Bring extra clothing and take the time to remove all wet clothing as soon as possible. Carry a smaller-sized emergency blanket for warmth, and modesty.

Treatment
First and foremost, get the person suffering from exposure into the warmest, driest conditions possible and nearby available shelter: a structure, tent or emergency blanket. Remove all wet clothes and replace them with dry articles, if possible. Cover the individual’s head and hands. Emergency blankets can reflect or retain 90 percent of a person’s remaining body heat. You should have one for each member of your party—these provide more options than sleeping bag.

This one sounds counter-intuitive, but limit the amount of motion. It takes more of the already depleted sugar supply to move, and the amount of heat generated is minimal. Even more important, excessive motion in certain individuals may instigate cardiac arrest according to experts.

If the person is able to swallow, start giving warm liquids such as bullion, honey water, tea, etc. Petroleum jelly- soaked cotton or one of the many commercial fire starters is a good way to start a wood fire for warming liquids and for warming the person suffering from hypothermia. The Esbit Emergency Pocket Stove is a handy way to heat water. Have stainless steel or aluminum bottles available in your kit or pack. Do not give alcoholic or caffeinated beverages to the patient and do not smoke or let the person have one, as these acts all restrict blood flow.

Begin to apply warm, dry compresses with emphasis on “warm.” Too much heat too soon can lead to an irregular heartbeat or exacerbate their condition. Chemical hand warmers are best because of their smaller size, instant-use capabilities, their long-lasting heat and can be air activated. Other sources are a metal water bottle with hot water wrapped in cloth or compresses that warm when squeezed or those that can stay heated for hours. Make sure heat is applied to the neck, chest and groin. Again, it’s counter-intuitive, but warming the hands and feet actually forces cold blood from these areas toward the core region. As a last resort, and because you can’t do anything else or don’t have the appropriate items, skin-to-skin body heat will work.

Have a plan—know who does what and when, leave a note where you are going and when you expect to get back. You can turn off your smartphone when you are out, but always have it with you, and charged. Remember, a small fanny pack will hold a lot: fire starters, a lighter and waterproof matches, instant heaters, small emergency blankets, etc.

Hypothermia is a sneaky thing and can happen in any season. But this condition can be prevented, is easily recognizable, and, if you are far from a hospital or an expert physician, you can immediately remedy the symptoms in the meantime.