BIG MOOSE TOWNSHIP, Maine -- 02/12/17 -- BDN reporter Aislinn Sarnacki stands in the clearing at the summit of Big Moose Mountain at 3,196 feet above sea level on Feb. 12, near Greenville. (Courtesy of Derek Runnells)

The group of college students prepared well for their winter camping trip, a loop through the high peaks of the Adirondacks. But they failed to notice when one of the young campers skipped breakfast, lunch and dinner. It wasn’t until she crawled into her sleeping bag early in the evening and wouldn’t wake up that they called for help.

The nearest park ranger, Ben Woodard, hurried to their campsite.

“It was a very scary situation,” Woodard said in a 2011 interview.

Though the college student’s breathing and pulse were nearly undetectable, he knew that she was hypothermic and might be revived if he acted quickly. Her body was too fragile to move on a sled, so they carried her a mile to the nearest cabin, still 6 miles into the backcountry.

Woodard made the cabin into a rainforest, heating it up with humidified air, and then set to work giving her mouth-to-mouth respiration all night, heating her up from her core. At about 3:30 in the morning, she responded to pain for the first time. By 5 a.m., she spoke to them and began accepting food and warm fluids.

“Hypothermia is a challenge to the body to maintain the body core temperature,” said Woodard, who was a seasonal ranger for 26 years in wilderness areas from Alaska to Maine before he became Baxter State Park chief ranger in January 2009. “It’s the cooling of the body core. That challenge happens through cold temperature, moisture and lack of calories that are needed for the body to maintain metabolism.”

Rangers and rescue teams at Baxter State Park carry insulating emergency blankets and a waterproofing layer year-round to aid anyone who is hypothermic or at risk of becoming hypothermic.

“Hypothermia is always a thought in our minds,” Woodard said. “We have below-freezing temperatures in the summer as well.”

Even if the temperature doesn’t go below freezing, there’s still the possibility of people who are spending time outdoors becoming hypothermic. For example, some hikers don’t carry enough warm gear to withstand the temperature dropping or wind picking up, which often occurs as you climb a mountain and gain elevation.

Injured people are especially vulnerable to developing hypothermia. An injured person is often immobile and covered in sweat, increasing the likelihood of the body’s core temperature dropping.

“It can happen any time the body is challenged to maintain its heat,” Woodard said.

Winter hikers should be aware that they’re going to be challenged by the cold. They should look out for each other, said Woodard, and be aware of the signs of hypothermia.

How to detect hypothermia

One alarming thing about hypothermia is that it causes confusion and lack of self awareness, therefore, someone who is hypothermic often doesn’t know it.

Symptoms of hypothermia usually occur in a progression. They start with involuntary shivering and loss of motor skills. Blood vessels shut down in the hands and feet. As body core temperature falls below 95 degrees, the shivering becomes violent. The person may slur speech or mumble, display illogical behavior, loss of emotional cognition or fight consciousness.

Below 92 degrees, the effects become life threatening, shivering stops, muscles become rigid, pupils dilate and pulse drops. By 86 degrees, the person is in a state known as the “metabolic icebox.” Breathing becomes shallow and erratic, consciousness is lost and the heart becomes vulnerable to deadly arrhythmia.

How to prevent hypothermia when spending time outdoors

Woodard says that people should always embark on an outdoor adventure such as a day hike ready to spend the night in the outdoors, equipped with extra clothing, water, food and a way of heating that food.

Keep your skin covered, including your head, in cold temperatures. Have a layering system of dry clothing that includes a waterproof, windproof layer and larger insulating layer for when you aren’t moving. Avoid wearing cotton, which traps in moisture. Opt for clothing made of synthetic materials and wool instead.

Eating food and drinking water consistently throughout the day is especially important in maintaining your body temperature outdoors.

“I think about metabolism in the body almost like a fire,” said Woodard. “Simple sugars and candies are the kindling. Carbohydrates such as snack bars are more like sticks. And then fats and proteins are logs and maintain heat for a long time.”

Daily water requirement is calculated at 1.5 liters, but dry, cold weather increases the loss of moisture through respiration. Keep in mind that thirst lags behind actual water requirements. A 10 percent hydration decrease will cause a 30 to 40 percent decrease in thermal control, according to Dr. William M. Forgey’s book “Hypothermia.”

Preparation isn’t all about what you carry in your pack. Leave a written itinerary for your outing with someone who will check in on you and make sure you return, that way rescue teams will know exactly where to look if you become lost or injured. And consider adventuring with a companion rather than alone. That way you can monitor each other for signs of hypothermia.

Avoid moisture. Acute hypothermia can develop in two hours or less. This usually happens when a person falls through a frozen lake or into frigid ocean water.

“Moisture [exacerbates] that body core cooling, so if someone falls through the ice or into the ocean, it happens a lot quicker,” Woodard said.

One man known for his studies of the human response to freezing water is thermophysiologist Gordon Giesbrecht, whom Outside magazine called “Dr. Popsicle.” He has lowered his body temperature to hypothermic levels 37 times during his research and has given demonstrations of the effects of hypothermia by intentionally falling through thin ice and remaining in the water until nearly unconscious.

His message is “1 minute, 10 minutes, 1 hour.” You need to control your breathing and survive the first minute after falling in ice water until numbness sets in. Then you have 10 minutes to move carefully before your muscles become useless. You should use this time to try to leave the water by treading water and lifting yourself onto surrounding ice, then rolling and crawling to land. If you can’t, keep your head above water, call for help, and if all else fails, place your arms on the surrounding ice so they freeze there and keep you afloat if you become unconscious. You have an hour before becoming acutely hypothermic.

The young woman in the Adirondacks is an example of a person developing chronic hypothermia, a lowering of the core temperature below 95 degrees Fahrenheit over a period of six hours or longer due to lack of insulation and calorie intake. This gradual development often progresses undetected. Preparation and being attentive to people in your group can prevent this type of hypothermia from developing.

How to help hypothermic people if medical care is not available

  • Get the person into a warm shelter. If pre-made shelter can’t be found, insulate the person from the ground with a waterproof layer and shield the person from rain and wind.
  • If the person is wearing any wet clothing, remove it.
  • Wrap them in an insulating blanket. The goal is to gradually warm the center of the body first — chest, neck, head and groin.
  • Warm beverages can help increase body temperature.
  • If in an enclosed shelter, heat up and humidify the air.
  • After body temperature has increased, keep the person dry and wrapped in a warm blanket, including the head and neck.
  • Get medical attention as soon as possible.
  • A person with severe hypothermia may be unconscious and may not seem to have a pulse or be breathing. CPR should continue while the victim is being warmed, until the victim responds.

Aislinn Sarnacki

Aislinn Sarnacki is a Maine outdoors writer and the author of three Maine hiking guidebooks including “Family Friendly Hikes in Maine.” Find her on Twitter and Facebook @1minhikegirl. You can also...