If you've ever been so cold that your teeth started chattering and your body began to shiver uncontrollably then you've experienced mild hypothermia. Most of us have been there, particularly when we were kids for indeed children are particularly prone to this potentially deadly condition.
Simply put, hypothermia occurs when heat loss from the body outstrips heat production. Even during mild weather hypothermia can occur for outside temperature is just one of a number of factors which contribute to the onset of the condition.
A tired cyclist cruising through the countryside on a fine spring day could be a potential hypothermia victim. If tired, the cyclist's energy reserves are already waning. Being, in all likelihood, sweat-soaked, the cyclist's garments will be sucking heat away from the body at a rate 240 times faster than at the start of the day when presumably the cyclist was dry. Even on a windless day the speed of the cyclist creates its own wind multiplying the rate of heat loss exponentially. Exertion is also contributing to the cyclist's quandary by causing dehydration through sweating and breathing.
Dumb is Dumber
All of these factors working in concert, dehydration and fatigue; outside temperature and dampness could spell disaster. The cyclist's inexperience more than anything else could prove deadly. Ignorance is the number one cause of this number one recreational killer. Armed with knowledge the cyclist can take simple precautions and avoid hypothermia in even its mildest form.
A savvy cyclist will dress in layers, shedding them as body temperature rises, donning them again as it drops. The inside layer will be a thin synthetic such as polypropylene that whisks moisture away from the body. Intermediate, insulative layers will be loose-fitting and made of fleece or wool. A breathable shell made of Gore-Tex will complete the package, acting as a barrier to rain, fog or condensation but at the same time allowing sweat in the form of water vapor to escape. Gloves, possibly in layers, and an insulating helmet liner complete the ensemble of a well-prepared cyclist.
Knowledge will further tell the cyclist that both water and energy will require regular replenishing and by habit the cyclist will frequently consume high-energy foods such as granola bars, trail mix and the like. Such foods contain sugars which provide immediate energy, carbohydrates which release their energy over a moderate period of time and oils and proteins which take the longest to be processed into usable energy by the body. That energy propels the bicycle forward, keeping the cyclist warm at the same time.
The informed cyclist will also recognize that chills and shivering are the earliest signs of hypothermia's onset. The cyclist will know that decision-making will soon become confused and coordination impaired if the condition is allowed to progress. Immediately the cyclist will switch from recreational mode to a survival-bent one, seeking ways to stabilize net heat loss from the body core.
Stumbles, Fumbles, Mumbles and Grumbles
If hypothermia progresses our cyclist must rely on companions to correctly assess the situation. The inexperienced may fail to notice the violent shivering, slurred speech, clumsiness, even irrationality that indicate their buddy is already suffering from moderate hypothermia. If they fail to intervene and the body core temperature of the victim continues to drop then unconsciousness, coma and finally death, all consequences of late-stage hypothermia, can be expected.
Treatment protocols of moderate to advanced hypothermia are complex and ever-changing. In the normal course of things, when adequate preparation and prevention measures are strictly adhered to, no one should ever get beyond the initial symptoms. Accidents do happen, however and a kayak spill in the west coast surf or a slip into an icy creek while hiking could be just the kind of event to precipitate the rapid onslaught of life-threatening hypothermia. The Wet Coast of British Columbia is aptly nicknamed because the conditions which prevail on Canada's west coast are ideal for hypothermia. Anyone, even casual recreationalists, who venture into the wilderness should consider taking a wilderness first-aid course which includes training in hypothermia prevention and treatment. Slipstream Wilderness First Aid offers regular, certified training at many levels of proficiency geared specifically for outdoor recreational settings.