#06–329 December 4, 2006

Dress properly, stay dry to prevent hypothermia

Hypothermia is a leading killer of outdoor enthusiasts, and hunters headed to the field should be aware of the threat and how to combat it. Hypothermia occurs when exposure to the wind, cold and wetness drain heat from the body faster than it can be produced.

“Extreme cold is not required for hypothermia to develop, and most cases occur when the air temperature is between 30 and 50 degrees,” said Lt. Jimmy Wagers, state coordinator of the hunter and boater education program for the S.C. Department of Natural Resources (DNR). Wind carries heat away from the body rapidly. Evaporation from any wet surface also draws heat from that surface.
           
“When the wind blows across a wet object, the object is cooled at a highly accelerated rate,” Wagers said. As a result, a wet person exposed to a breeze can become hypothermic in a short time, even on a mild day. Once hypothermia sets in, death can occur unless immediate action is taken.
           
“The best way to combat hypothermia is to dress properly and avoid getting wet,” Wagers said. A non-absorbent, wicking layer of underwear of polypropylene or similar synthetic, covered by layers of wool, and a waterproof shell would be good in most wet-weather situations. The waterproof rain gear can be carried in a small daypack, but should be donned before the other clothes become wet.
           
Wagers said that once a person gets wet, he or she risks hypothermia, whether from a fall into the river while fishing, from splash and spray while rafting, from excessive perspiration on a cold day, from leaky waders while duck hunting or from hiking in rain or snow. Coast Guard approved float coats offer good protection when boating in cold weather. “Wet clothing should be exchanged for dry clothing as soon as possible, especially if a breeze is blowing,” Wagers said. Getting out of the wind and rain promptly can mean the difference between a safe outing and a life-threatening ordeal.
           
One of the most important defenses against hypothermia is recognition and treatment of the early symptoms. Uncontrolled shivering is the first signal that excessive exposure is occurring and that hypothermia is impending. It is also one of the few symptoms the victim may recognize himself.
           
As hypothermia sets in, slurred speech, frequent stumbling, loss of manual dexterity, memory lapses, exhaustion and drowsiness occur. Often a victim will not notice these signs, so partners should watch each other when wind, water or cold create the potential for hypothermia.
           
“It is wise to get out of the wind and cold, remove wet clothing, and warm the body before hypothermia sets in,” Wagers said. Once the telltale symptoms are recognized in any member of the party, these steps are absolutely critical: Stop, take shelter, remove wet clothes and warm the body.
           
If only mild impairment is evident, warm drinks and dry clothes will probably solve the problem. High-energy foods can help provide fuel for metabolic heat production. Powdered sweetened gelatin mixed with warm water makes a high-energy emergency drink. A warming fire can help speed the recovery.
           
In advanced cases of hypothermia, drowsiness may lead to unconsciousness. Attempt to keep the patient awake, and give warm drinks. The victim should be placed in a sleeping bag with a heat source. Skin to skin contact (especially chest-to-chest) from another person is the best treatment. Warmed rocks may also be wrapped and placed in the sleeping bag. A fire can help warm the camp and supply desperately needed heat.
           
The early warning signs of hypothermia result as the body shuts down circulation to the limbs and nonessential organs in an attempt to maintain the core temperature. As more energy is drained, survival becomes dependent upon stopping the outflow of heat and supplying warmth from external sources.
           
“Awareness of the signs followed by prompt attention to the problem can save lives,” Wagers said. “Keep hypothermia in mind whenever you are outdoors and the weather turns wet or cold.”

For more information, call the DNR hunter and boater education office in Columbia at (803) 734-3995.