As Spring approaches, keep in mind that just because it’s reaching 70+ degrees in Arizona, it’s still only reaching 40 in Michigan. Those are the extremes, and we can pretty much tell the difference between the North and the South. However, what about places like the Smoky Mountains, or the Grand Canyon. These backpacking destinations are often overlooked when planning on what to wear. It can reach 70 during the day, and freezing temps during the night. I keep one rule in mind when I hike in the Spring, especially at higher elevations. “Plan for the worse, hope for the best”.
Of course, that’s not to say my pride has never been wounded, sometimes quite uncomfortably so. Nonetheless, I’ve never actually been hypothermic, the condition in which the body’s core temperature drops low enough to impair normal muscular and mental function. In February I hiked the first 30 miles of the Appalachian Trail. 50 degrees during the day (awesome weather) but 20 degrees at night. No matter how you plan for the weather, you need to know the signs of Hypothermia.
Hypothermia begins with a sensation of chilliness, numb skin, shivering and loss of coordination and strength in the hands. It progresses to more severe shivering and loss of overall muscular coordination. Victims begin to stumble and fall frequently. Hands become numb, useless claws. Thought and speech slow to a crawl. Severely hypothermic victims lose the ability to walk and become incoherent and irrational. If cooling continues, death occurs because of heart failure.
Treatment for moderately hypothermic victims is simple: rewarming, starting with the trunk. Simply adding more clothing does not help, because hypothermia victims have lost the ability to rewarm themselves. Adding more clothing only serves to reduce the rate of heat loss; it does nothing to actually rewarm the body. To do that, external heat must be applied. The easiest way to do that in the field is to zip two sleeping bags together and have a warm rescuer climb inside with the victim. A conscious victim should drink warm liquids; however, you should never try to force an unconscious victim to drink. They’re likely to choke. Severely hypothermic victims require hospital care.
The key to preventing hypothermia is staying dry. Good shell clothing will ward off rain and snow. Preventing sweat from soaking your clothing is more difficult. If you let yourself sweat while working hard in the cold, you’ll get chilled when you stop. Despite the obvious threat of discomfort, however, sweating seems almost impossible to avoid.
In cold weather, you must consciously fight your natural tendency to sweat. That means dressing in layers that can be removed to prevent sweating when you’re working hard and added to hold in heat when you stop moving. The human body generates about five times as much heat when hiking with a load as it does when at rest. Savvy backpackers adjust clothing as often as needed to remain comfortable.
Hypothermia cases are by no means limited to the winter months. In fact, hypothermia is actually quite common in the summer, when inexperienced and poorly prepared hikers get caught above timberline by a 40-degree rainstorm and 20-mph wind – a potentially lethal combination
Have a good hike, and I’ll see you on the trail.