Don’t Overlook The Risk Of Hypothermia

This time of year, when temperatures start to warm and daylight lingers, many people overlook the risk of hypothermia risks because winter is almost over.

But the possibility of hypothermia is especially important to consider in motorized outdoor recreation virtually any time of year.

Most people don’t really know what hypothermia is. Oh, they have some idea that “you get too cold and you might die,” but through their ignorance they take a serious subject lightly.

Hypothermia is the cooling of a body faster than it can generate heat. In the outdoor world, virtually everything you come in contact with is trying to take heat away from your warm body: lakes or streams, snowfields, the ocean, or even our ocean of cold air. And when you choose to move through the elements rapidly with powered recreational pursuits, the risk increases.

A mammalian body like ours is a chemical engine. One of the byproducts of the engine’s work is heat. Our bodies produce heat a couple of ways.

Normal metabolism - including digestion, breathing and pumping blood - generates some heat. But firing up and moving our big skeletal muscles generates more.

Motorized vehicles - snowmobiles, for example - increase the risk of hypothermia in two ways. First, cold moving air carries away heat from our bodies faster (the wind chill factor) And, secondly, we’re not using our big muscles for locomotion, which means our bodies are generating less heat.

So how cold does it have to be to be at risk? A naked human will begin to lose heat to the environment faster than he or she can generate it at 77 degrees, unless there is a mental, physical or physiological response to counter the drop.

Bodies lose heat three ways.

Radiation heat loss accounts for some 50 to 65 percent of the total heat output.

Conduction losses can occur when a warm body comes in contact with a cold object, like the ground or a boat seat.

Convection loss occurs when cold wind or cold water rushes over a body, constantly removing the heat generated. This is the killer for motorized recreationists. Think of the wind as a big vacuum cleaner that sucks heat out of your body. The more you can stay protected from the wind and the drier you stay, the slower you’ll lose heat.

Fortunately, manufacturers of outdoor gear for snowmobilers and foul-weather boaters understand these risks and have developed snowmobile suits and coldwater survival suits incorporating extraordinary fabric technology.

On the downside, these outfits are expensive, some mobility is sacrificed, and while they may protect from hypothermia, they can’t completely prevent it.

There are two types of hypothermia, too. Chronic hypothermia results from exhaustion and dehydration. Acute hypothermia involves losing 5 degrees of core temperature in less than two hours.

For most outdoor recreationists at this time of year, the greatest hypothermia risk comes from the acute form. An overturned boat or a night in the woods with a brokendown snowmobile will take you about as close to death as you’ll want.

A low body core temperature affects chemical reactions in the brain, resulting in poor or even absent judgment. This makes self rescue difficult or impossible.

Hypothermia victims will sometimes do bizarre things like taking off their clothes, walking in circles or driving snow machines away from groups.

One way to reduce the risk is to travel with other people. Clubs provide not only a social element but a safety element, too. Not only is winter recreation more fun with friends and family, it’s safer.