The one thing I love about winter hiking—besides the satisfying crunch of snow underfoot or the crystalline scenery—is the guilt-free ticket to consume carbs. I eagerly toss the bag of M&M’s and Craisin gorp into my pack because I know that stash is cheap fuel for my core, and one of the best means of preventing and treating hypothermia. So too is observation, which can sometimes lapse in the excitement of being out in the white stuff. We may ignore the slight, persistent shivers, or we may think our partner’s growing irritation is merely about elevation gain, but it may also be our bodies raising red flags, easily recognizable and treatable if we know how to act.
Shivering can be good. It’s the first physical indication that your core body temperature is dropping. When ignored, shivering can progress from easily dealt with to constant and uncontrollable as your body works harder to warm up. Vasoconstriction—or reduced blood flow—also occurs in your extremities as heat is corralled around your core. Grumpiness or quietness can often be another signal of mild hypothermia setting in and mental ability becoming impaired. One of the worst things you can do, AMC Leadership Training Coordinator Jess Wilson says, is to sit someone down who seems hypothermic. “You really need to get them up and moving around,” she says. “Quick interventions” like briskly walking along the trail or doing jumping jacks works the large muscles and creates the energy needed to return to normal body temperature. But, Wilson adds, exercise needs to be balanced with metabolic fuel intake to power those muscles.
Simple carbohydrates, or sugars, are the quickest vehicles of energy production that we can feed ourselves. As for the great outdoors trailhead the hypothermic person moves around, he or she should also munch on a candy bar, gorp, a piece of fruit, or anything with sugar. Wilson recommends keeping extra carbs, like a candy bar or sugary drink mix, in your first aid kit. “You know that it’s always there if you need it,” she says.
Consuming liquids is also critical, as dehydration can trigger hypothermia. If we don’t replace the water we lose during exercise, our blood thickens and becomes sluggish, decreasing circulation and speeding heat loss. Contrary to popular belief, the temperature of the water has little to no effect on how quickly it is absorbed. “Taking the time to heat up water isn’t worth it,” Wilson explains. “When core body temperature is lowered, whatever treated water you have on hand is going to be beneficial.” There is, of course, a psychological benefit to warm liquids, so make the hot cocoa when you reach your destination or pack a thermos-full beforehand.
Water conducts heat away from the body up to 25 times faster than air, which means anything wet next to your skin is going to be one giant heat sponge. Wet layers compound hypothermia, and Wilson says it is important to remove them, “even if all [the person] has is a fleece, even if he doesn’t have a base layer to put back on. If something is soaking wet, it’s going to lose heat.” Ideally, good trip planners have dry base layers in their packs, along with an insulating mid-weight layer and a waterproof/windproof shell. A down jacket is also a good warm layer to put on during rest stops or at camp. The same principles apply with moderate hypothermia, but oftentimes the person is unable to walk. Wilson then advises making a “hypo wrap,” or “human burrito,” to “trap what little heat they are producing.” Dry base layers and a waterproof, windproof layer are crucial first steps. Laying the person on one or more closed cell foam sleeping pads will get him off the heat-robbing ground. Putting the person in one or more sleeping bags will further aid recovery. But be careful: “People always want to put two people in a sleeping bag together, but that’s generally not [viewed] as a good practice anymore,” Wilson says. The warm person might overheat and sweat, getting both people damp and chilled. Or, you might end up with a second hypothermia patient if the first is very cold and the burrito not adequate.
Once physical mobility returns, the hypothermic person should resume exercising the large muscle groups. Calorie and water consumption should also continue during recovery, as long as the person is able to eat and drink. In cases of moderate to severe hypothermia, when symptoms do not improve or if a person loses consciousness, emergency medical help should be sought out immediately.
So, pack a healthy amount of M&M’s and Craisin gorp, or any other sugar-laden food, and don’t forget your water. It’s all part of your emergency kit in fending off and treating hypothermia.