Hypothermia can kill
fishers in winter!

December 20, 2004
Base article written by Mike Creel- SC DNR.
Images by Bill Byrd.
Modified and Edited by Bill Byrd.

With winter temperatures anglers should be aware of the threat of hypothermia and how to combat it, say state natural resources officials. "Hypothermia occurs when exposure to wind, cold and wetness drains heat from the body faster than it can be produced," said Lt. Joey Rentiers, hunter and boater education coordinator for the S.C. Department of Natural Resources.

Whether we are wading a stream, fishing from a float tube or belly boat, or fishing from a boat we all need to be sure to heed the symptoms of hypothermia. In each case exposure to the elements is the starting point for hypothermia, and the conditions that produce hypothermia may be subtle.

Extreme cold is not required for hypothermia to develop, and most cases occurs when the air temperature is between 30 and 50 degrees. Wind helps accelerate body heat loss, and 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," Rentiers said. As a result, a wet person exposed to a breeze can become hypothermic in a short time, even on a mild day.

This time of year when I fish I always carry a complete change of clothing and an extra layer of polar fleece. If I were to fall overboard, become wet from perspiration inside of waders in cold water, or have a wader leak, I can get out of my gear, change to warm, dry clothing, and get warmed up again. If I am wading and slip taking a dip in cold water, I get out immediately to change clothing and put on spare, dry waders.

One thing I discovered over several seasons of fishing from float tubes in winter is VERY subtle. I couldn't keep my legs and feet warm after an hour of fishing from a float tube in waters as cold as the upper 40s down to the upper 30s. From my waist up I was very comfortable. After trying every imaginable combination of socks and water wicking clothing I realized a simple fact.

Sitting in the seat straps of a float tube with my body weight on the straps cuts off circulation through the rear of my legs, making my legs and feet go cold and eventually numb. It is lack of circulation that causes this to occur. I simply get out of the tube for a few minutes every hour and move around to restore good circultion and temperature to my legs and feet. I always warmed up a little when I hooked a giant bluegill hanging deep in cover in the dead of winter -- see image above right.

Another issue in a float tube system or while wading is water pressure on our submerged extremities. Water pressure exerts force against our feet and legs while submerged. It causes our normally loose fitting layers of warm clothing to compress against our skin. This cuts out the air space that we use to warm with body and insulate us from the cold.

By compressing these air spaces, our ability to keep warm in these submerged body areas is greatly diminished. In fact water absorbs away body heat at a rate 7 times that of air. When we have on insulated water wicking under clothing and clothing and water pressure compresses the heated air spaces around our submerged extremities, we begin losing body heat in these areas at rates approaching the 7 times greater than air loss figures. It is easy to see why float tubing and wading can produce some cold legs and feet!

Once our legs and feet start to cool, our bio feedback system further shuts blood flow to the chilled area to preserve body heat and keep up core temperature. That is why, even though I love fishing from float tubes because I catch some wonderful fish from them, in winter I fish from a boat as much as possible.

In a boat our legs and feet aren't submerged, so we don't experience this clothing compression problem. It is much easier to remain warm out of the water. Loose moisture wicking clothing in layers establishes air spaces or heat to build up and wicks away moisture that would further cool us. In my boat in winter I am comfortable no matter what the temperature. It is easier to carry along hot coffee, tea, or soup, chili, and cornbread to warm up with while on the water. I still carry a full change of clothing in case of a fall overboard.

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," Rentiers 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. Gore-tex based outer garments and hats repel rain, wick out moisture, and help keep us drier, too. Winter fishing gloves (like in the image above right) will make your hands 10 degrees warmer whether wet or dry.

We can catch some really nice fish on very old days. The waters are usually clear of most fishers. The main rule is to be prepared for conditions. Waterproof rain gear can be carried in a small daypack, but should be donned before the other clothes become wet. Rentiers said that once a person gets wet, he 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," Rentiers 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," Rentiers 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 of hypothermia followed by prompt attention to the problem can save lives," Rentiers said." Keep hypothermia in mind whenever you are outdoors and the weather turns wet or cold." Carry a change of clothing and be prepared.