Every year in the United States, about 1,300 people die from hypothermia. Many never see it coming—the condition can strike hikers and hunters even in the summer months, and it has a way of sneaking up on people.
Thankfully, it’s relatively easy to avoid and to treat. Knowing how to treat hypothermia can keep a piece of bad luck—like an unexpected downpour, winter car breakdown, or a twisted ankle on the trail—from turning deadly.
1. Know the signs
The early symptoms of hypothermia are pretty obvious: the body shakes, teeth chatter, etc. Basically… you’re cold.
But as body temperature dips (hypothermia officially begins when body temperature reaches 95 degrees Fahrenheit), the symptoms become more serious.
Todd Miner, who teaches wilderness medicine at the University of Colorado, said to look out for “the umbles”: fumbling, mumbling, stumbling, and grumbling. These are signs of an altered mental status, said Miner, and should be taken very seriously.
“Once you get hypothermic, it’s insidious,” said Miner. “It impacts the brain, you don’t know what’s happening, quit taking care of yourself, and lose the ability to respond. Once it starts, without corrective action, you start a downward spiral that can lead to nasty outcomes.”
From this initial state of confusion, hypothermia can get serious very quickly. The pulse weakens, respiration slows, and delirium starts to set in. Once body temperature dips into the mid-80s, it’s not uncommon for hypothermia victims to experience a sudden rush of warmth as blood flows away from their core and toward their extremities. This feeling often causes people to strip off their insulating layers, which is of course a very bad idea.
2. Stay Dry
The easiest way to avoid hypothermia? Don’t get wet.
“It’s hard to get hypothermic in cold, dry conditions,” said John W. Castellani, Ph.D., a physiologist for the U.S. Army. “You have to be out a long time—more than a day—with very poor insulation, unless it’s brutally cold, below 0° F.”
The body loses heat 25 times faster when wet, making hypothermia possible even in moderate conditions. That’s what killed four Army Ranger candidates in Florida in 1995; soaked in 52-degree water, the group froze to death despite air temperatures in the mid-60s.
If hyopthermia seems like even a remote possibility, stay dry at all costs. Pack rain gear for every outdoor excursion, and avoid cotton clothing, which loses its insulating power when wet. Avoid bodies of water if possible, and never walk on ice unless you’re 100% sure it won’t break.
3. If you fall in, remember 1-10-1
If you do punch through thin ice, you’ll be in trouble. But not as much trouble as you might think.
“You won’t die in 10 minutes if you keep your wits about you,” said Castellani. He cites the “1-10-1 rule,” which describes the risk of cold water as occurring in three stages.
First, you’ll experience a cold shock. For about one minute, you’ll likely panic and hyperventilate. This will put you at risk of inhaling water, so focus on keeping your airway above water during this period.
From there, you’ll have about 10 minutes to get out of the water. After that, your muscles will shut down and you’ll be unable to extract yourself.
If you’re unable to completely extract yourself from the water, Castellani recommends holding your arms on the ice until they freeze there. The ice will then hold you above the water line, and you’ll have about one hour before you become seriously hypothermic.
