About 600 people die each year in American from excessive cold. Hypothermia can occur when the body temperature drops below 95 degrees as a result of prolonged exposure to cold temperatures. In extreme cases, it can cause death.

Because the body loses heat faster than it produces it, hypothermia can take a person by surprise, making it especially dangerous.

Know The Symptoms

* Cold weather, extreme dampness, or the rapid loss of body heat because of clothing made wet by perspiration can all lead to hypothermia. However, even prolonged exposure to relatively mild temperatures can cause some individuals to lose too much body heat. In fact, some experts say most hypothermia cases occur in air temperatures between 30 and 50 degrees.

* When you feel uncomfortably cold, you are having the first warning of hypothermia. Muscle tension, fatigue, and uncontrollable shivering may follow.

* Other danger signs include poor coordination, slurred speech, and blue or pale lips or fingertips. Eventually these symptoms lead to drowsiness and apparent exhaustion. A person who reaches this stage may be confused or irrational and insist there is nothing wrong. Don't believe it. Even a healthy person can be killed by exposure in only four hours.

* If you see someone with the symptoms of hypothermia, don't take no for an answer. Get the person to a shelter and seek medical attention immediately.

To Protect Yourself

* A well designed apparel system will have at least three layers: underwear, insulation and an outer shell. Each component must work with the others to prevent you from becoming wet from sweat and the elements.

* Begin with thermal underwear or synthetic fibers such as polypropylene. This allows perspiration to escape. Don't wear cotton next to the skin.

* Wool and synthetic fiber garments are preferred for the middle layer(s) because they stay warm when wet.

* A waterproof windbreaker should be the outer layer. Shed the layers as you begin to perspire.

* Woolen socks over a polypropylene inner sock are a good combination.

* Up to 50 percent of body heat is lost through the head, so a hat is a must.

* Mittens are more effective than gloves because they allow heat to pass between the fingers.

* Avoid tight-fitting clothes and boots that may restrict circulation.

* Avoid overdressing. Movement generates body heat. If that heat is retained by external layers of clothing, it can cause premature fatigue and discomfort.

* Note: You're probably overdressed if you don't feel slightly chilled during the first five minutes of being in the cold.

* Eat a good meal to have the calories necessary to keep your body warm. Take along a thermos full of coffee or hot soup.

* Keep dry by not working up a sweat. If you're shoveling snow, or otherwise exerting yourself, shed a layer or two of clothing to keep from perspiring.

* Try to keep the wind at your back, and take periodic breaks.

* Use the "buddy" system or let someone know where you are and when to expect you.

* Avoid nicotine and alcohol. They dilate the blood vessels, which increases your heat loss. Certain drugs may have the same effect. Check your doctor.

So, You Just Have To Get Out

Regardless of the weather, some hearty souls insist on frolicking in the cold. That's cool, so long as they use good judgment.

Joggers and runners are at special risk of hypothermia because their movement can increase the force of cold winds against their bodies, especially when there's a lot of moisture on their skin. If you are exercising outdoors:

* Wear modern synthetic long johns that keep moisture away from your body.

* Walk or run against the wind at the start, so you can return home with the wind at your back.

* Drink enough fluids.

* Know the route you're planning to run.

* Get back before extreme fatigue sets in.

* Carry concentrated snack foods, such as raisins, nuts, peanut butter, chocolate, or dried fruit.

* Wear mittens and a polypropylene hat. Spread a thin layer of petroleum jelly on exposed skin areas