Key Points

Cold-weather exercise requires proper layering of synthetic clothing with a waterproof, breathable outer layer to maintain body temperature, but excessive sweating or environmental dampness should be avoided.

Hypothermia victims should be sheltered, dried, and warmed, and resuscitation attempts should continue until body temperature is higher than 32° C.

Outdoor sports participation, particularly winter sports, places athletes at risk for cold-induced injury. Two problems commonly encountered are frostbite and hypothermia.

Frostbite most frequently affects the toes, fingers, and exposed skin of the face. As tissue cools, a progressive cell membrane leak results initially in increased extracellular fluid, with progression to extracellular ice crystal formation and then ischemic necrosis. Prevention includes dry layering of clothing that is not constricting; avoidance of skin exposure, especially in windy, cold conditions; and maintaining the core temperature, because hypothermic shunting of blood centrally promotes distal extremity freezing. Treatment involves warming, although this is not recommended until the victim has been safely evacuated—warming and then refreezing is more damaging. Antibiotics, tissue debridement, and possibly amputation may be required, depending on the extent of injury. Sallis and Chassay (1999) provide a more in-depth discussion of frostbite and other cold-induced injuries.

Hypothermia is defined as a core temperature at or below 32° C (90° F). Lower ambient temperatures and longer exposure times increase the risk for hypothermia, but moisture is the most dangerous variable that must be controlled. Wet clothing results in significant increases in conductive heat loss, which is made worse in the wind. Prevention of hypothermia requires proper clothing for outdoor exercise in the cold. Clothing should be layered so that with increased exertion and endogenous heat production, layers can be removed to avoid excessive sweating. Underlayers should consist of breathable wicking fabrics that move sweat moisture away from the skin. Outer layers should be windproof, waterproof, and breathable. Midlayers, which can be added depending on the temperature and exertion level, should provide loft (synthetic pile or down) to trap air; this provides a temperature gradient between the warm underlayers and cold outer layers, much like the blubber on a marine mammal. Heat loss from the head is significant, so a hat or hood that wicks moisture is necessary, and mittens are warmer than gloves for very cold weather. Dehydration must be avoided, because low plasma volume results in peripheral vasoconstriction and increases the risk of frostbite.

Treatment of mild hypothermia involves finding warm shelter away from the wind, removing wet outer layers, and covering with dry blankets. Sharing a sleeping bag with a warm climbing partner can be lifesaving in a desperate situation. In the setting of severe hypothermia, warm IV fluid (40° C), warm humidified oxygen, and warming lamps are indicated, if available. The adage "one is not dead until warm and dead" applies, and ventricular fibrillation or asystole in the settling of hypothermia should be treated with advanced cardiac life support (ACLS) protocols until the patient has a core temperature above 32° C (Sallis and Chassay, 1999; Tom et al., 1994).

Soccer Fitness 101

Soccer Fitness 101

Be a star on the field in no time! Get Fit For The Soccer Field In 10 Easy Steps! With soccer season looming just around the corner it’s never too early to start getting ready. Soccer is an intense game, and it’s going to take a lot of work on your part to make sure that you’re ready to stay ahead of your competition out on that field.

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