Those in the search and rescue business call it the “umbles.”

As moderate hypothermia overtakes someone, they start to "mumble" their speech. Then they start to "grumble" and whine a bit. They "fumble" and "bumble", having trouble with things like backpack straps or zippers as they shiver and behave irrationally. Walking could lead to a "stumble", like being intoxicated, and even a "tumble".

The end result of these symptoms can be death.

Spring and fall are probably the trickiest for people. They’re not always thinking about the weather, especially in the mountains. In February, they think cold and snow, but not in April, May, October and November.

Recently a Massachusetts hiker was found dead by the Appalachian Trail in Norwich, Vermont. The medical examiner ruled death was caused by hypothermia. The person who found the body, an avid winter camper, summarized that the cause of death was due to being ill-prepared on the trails. 

Out for a walk, he found the hiker’s gear in the woods strewn about in an unnatural way and notified police.

“All the evidence to me pointed to the likelihood that the gear's owner might have been hypothermic and wandered off,” he said. “Sparing unnecessary details, what really struck me was the inappropriate equipment for someone backpacking in late March: a cotton sleeping bag, no tent, cotton clothing, and 2 pairs of low-cut trail shoes (i.e. no boots).” 

Hypothermia is the cooling of the body core temperature caused by heat loss and the body’s inability to keep the internal temperature constant. It can happen year-round, particularly on those days of rain and wind when the temperature is between 40 and 60 degrees.

Last fall an experienced thru-hiker on the AT died on Mount Madison because of hypothermia. This winter an experienced canoeist overturned his boat, swam to shore and died from hypothermia in central New Hampshire.

Hypothermia is one of the all-time greatest killers of unprepared adventurers. It can sneak up on you.

Temperature change impacts the brain. If people get cold, they lose their ability to function.

Prevention is key. To prevent heat loss, keep hands and head covered. Forget cotton. Dress in layers starting with wicking underwear. Drink plenty of water and eat lots of food to get those heat-generating calories. Take rest stops to avoid perspiration. Carry emergency gear like a foam pad for sitting and a good insulated jacket or sleeping bag for warmth and extra food and water.

You can have all the greatest clothing and gear, but with no food and water, you are not going to stay warm. 

Symptoms of hypothermia include bad judgment, confusion, forgetfulness, loss of motor control and coordination, uncontrollable shivering, cold feet and hands and fatigue. Act quickly should they appear.

There are three big things to remember. Fix that person’s layering system and get them warm and dry. Get them food and water because you need fuel in the form of sugar. Get them moving. Moving muscles generate heat. Moving people does wonders.

If getting someone moving isn’t initially possible, warm them up in a sleeping bag. If you have a stove, heat water and put hot water bottles around the person’s neck, armpits and groin. Start a fire.

Those hiking in groups should look out for each other.

Trip leaders should be able to recognize it early. Step in and do something to reverse it before it gets worse.

Not everyone hikes in groups or in pairs. There are those who venture out alone.

You have to keep checking on yourself. If you have gotten too wet, get dry. Take the time and make the effort to monitor yourself. Hiking alone is a skill to acquire with practice.