How Not to Die of Hypothermia on the Appalachian Trail

Learn how to protect yourself from Hypothermia on the Appalachian Trail

Are you a beginning overnight hiker looking to lace up your boots and tread some miles on the AT? Read this article to learn how to protect yourself from the elements. These concepts might just save your life.

Every year hundreds of thousands of hikers make the trek north or south along the Appalachian Trail (AT), which extends from Springer Mountain in Northern Georgia to Mount Katahdin in Maine. While deaths from hypothermia are rare, they do happen, and the cold can strike hikers anywhere and at any time on the trail.

What exactly is hypothermia?

Hypothermia comes from the Greek words hypo and therme, and literally means "under heat." When your body is unable to generate enough heat to keep you warm, your core body temperature, normally at 98.6 degrees, will begin to fall. When your temperature passes below 95 degrees, you have entered a state of hypothermia. Symptoms include slurred speech, fatigue and tiredness, and lack of coordination - the latter two of these symptoms are especially treacherous, because they can actually prevent you from taking action to regain your warmth. You don't have to be in a snow storm to become hypothermic; any prolonged period of exposure, where you are in the wind, rain, or cold unprotected, can cause your core temperature to drop to dangerous levels.

How do we fight it?

The most important way to avoid falling prey to hypothermia is to adopt the Boy Scout's motto: Be Prepared. Long before you set foot on the trail, you should have formulated a plan for dealing with adverse weather - including the cold. This includes knowing the weather in the area you plan on hiking during the time of year you set out. This also includes bringing the proper equipment for the amount of time you plan to spend on the trail.

Bring the proper equipment

I am primarily an overnight backpacker, meaning that I bring enough equipment to hike several miles onto the trail. I then make camp, spend the night, and reverse course and hike to my car the following morning. Accordingly, I bring what I need to keep me warm during all phases of the hike. This includes:

• Warm head cover
• Warm jacket
• Warm sleeping bag
• Durable tent
• Sleeping pad

Maintain a barrier 

While you are sleeping the most important way to avoid hypothermia is to 1) remain dry 2) be outside the wind and 3) be raised off the ground.

Remain Dry

When you or your clothes are wet, or even damp, you lose heat much more rapidly than you do when you are dry. In fact, this is why your body sweats when you become overheated; as sweat evaporates, it cools you down. In cold conditions, this can be deadly. 

Further, when your clothing becomes wet, it becomes much less effective in insulating you against the cold and the wind. This is why it's important to keep equipment such as your jacket or head cover dry at all times. Indeed, during a cold hike, I try to limit my pace to be sure I don't sweat excessively and soak my clothing from the inside-out! I also bring "dry bags," or large, lightweight bags that can be closed with a water tight seal, so that I can shield my clothing or sleeping bag from moisture should the need arise. I likewise line the inside of my backpack with a plastic trash bag to keep rain from seeping inside.

Stay out of the wind

Even when you are dry, exposure to the direct wind can quickly siphon off your warmth. Your first line of defense against the air is your jacket and head cover. But I'm always grateful for the protection of a solid tent when I make camp near the top on one of North Georgia's windy foothills. When all else fails, you can always find a natural barrier between yourself and the wind, such as a fallen tree, rocky outcrop, or the side of a hill.

Keep off the ground

The last crucial element of your barrier against the cold is staying off the ground when you decide to sleep. It's also possible that you might have to lay on the ground if you find yourself injured on the trail and are unable to walk. No matter the situation, spending a long time with your body against the cold ground can rapidly drain your body's internal heat. I carry a plastic foam sleeping pad, basically a yoga mat, and place it under my body when I sleep. This keeps my back and butt warm because they aren't in contact with the cold ground.

Have a "Plan B"

While I'm confident the strategy above will keep me warm in 99.9 percent of scenarios I might face, I like to have a backup plan in case Nature decides to throw her full fury in my direction. How will I avoid hypothermia if

• most of my equipment becomes wet, or my tent is damaged by a rogue gust of wind;
• I'm on the top of a gusty hill where the temperature might remain in the low 10s all night;
• I'm injured and can't leave the hill before the morning?

I always carry a fixed blade with me, and sometimes a small folding saw. This allows me to gather firewood from dead trees in the area and make a small fire. The basic steps are:

1. Use the folding saw to cut down a dry piece of dead wood, like a small dead tree
2. Saw the piece of deadwood into sections about the length of your forearm
3. Grab a section of wood and place it upright. Place your knife edge horizontally on the top of the wood, as if you were going to slice it down the center.
4. Using another section of the log like a "baton," hit down on the knife until it bites into the wood.
5. Continue hitting the knife with the baton and drive the knife through the center of the log.
6. Once the log is split, continue splitting other logs, or split the new pieces into smaller sections.

The batoning technique can allow you to make a fire by accessing the inner-wood of dead trees, which is often still dry - unlike wood you find lying on the ground, which is usually full of moisture and won't burn.

Stay safe - and warm!

Overnight hiking is a great way to take a mini-vacation from the world for a weekend. I find I enjoy hiking even more when the weather is cool or even cold, as hiking long miles during the day under a hot sun can make for a miserable experience. If you plan accordingly and ensure you bring the right equipment and understand the fundamentals about how you can avoid exposure to the cold elements, you have little to fear about hypothermia during your overnight backpacking adventure.

Indeed, there are many styles of backpacking; some are minimalists, some, like myself, are often tempted to bring everything in my backpack except for the kitchen sink. If you're new to overnight hiking, I would encourage you to experiment and find your own style for how you want to spend a night in the woods.