Get Outdoors - Prevention: Prevent Hypothermia

Lowered body temperature occurs when a person cannot be adequately protected against a cold environment. This is a greater risk when a person is immersed in water or dressed in wet clothing.What is hypothermia?

Mild hypothermia - a core (measured rectally) body temperature 98.6^o F (37^o C) and 95^oF (35^o C).
Moderate hypothermia - a core body temperature 95^o F (35^oC) and 90^o F (32.2^o C).
Severe hypothermia - a core body temperature 90^o F(32.2^o C).
Immersion hypothermia - the particular case in which a victim has become hypothermic because of sudden immersion into cold water. Water has a thermal conductivity, 25 times greater than air, and a person immersed in cold water transfers heat, 100 times as fast from the skin into the water as into air.

What causes hypothermia?

Heat is lost from the body to the environment by direct contact (conduction), air movement (convection), infrared energy emission (radiation), the conversion of liquid (sweat) to a gas (evaporation), and the exhalation of heated air from the lungs (respiration).How do I prevent hypothermia?

Stay dry. If you do get wet, change immediately into dry clothes.
Do not exhaust yourself in cold weather. Avoid perspiring.
Dress in wool and synthetic layers. Avoid cotton because it takes a long time to dry. Adjust clothing for overcooling, overheating, perspiration,and external moisture.
Bring extra clothing (including wood or synthetic hat and socks) so you are prepared for the worst possible weather conditions.
Stay hydrated. Drink at least 3 to 4 liters of fluid daily. During extreme exercise, drink more (5 to 6 liters per day).

Ingesting snow is an inefficient way to replace water, as it worsens hypothermia. At night, fill a container with at least one quart of water,and sleep with it to keep it from freezing.

Do not skip meals; you need food (fuel) for your body to generate heat. Do not consume alcoholic beverages; alcohol impairs your body''s ability to remain warm.
Seek shelter in times of extreme cold and high winds.
Don''t sit on cold rocks, metal, snow or ice without insulation beneath you. Insulate yourself from the ground with a pad, backpack, log, or tree limb.