A serious life-threatening condition. It happens when the body's core internal temperature drops below the point where normal body functions occur. It is different than frostbite or freezing to death. Hypothermia is one of the greatest dangers when you go out on the water. It is usually thought of a cold-weather or cold-water condition; but it can occur at temperatures well above freezing, even in waters as warm as 80°. Whenever you go boating or swimming, you need to understand and look for the signs of hypothermia.
Early signs of Hypothermia:
Hypothermia happens when the body loses heat faster than it can replenish it. One of the first signs that your body is losing heat is shivering and "goosebumps". As your body temperature falls, the shivering slows, then stops. This is your body starting to shut down. It takes too much energy, and expends too much heat, to shiver. The flow of blood to your arms and legs slows, then stops. As you go into the deeper stages of hypothermia, your speech becomes slurred, then incoherent. Eventually, you become lethargic and your motions are uncoordinated. Your breathing slows, becomes shallow and erratic. You lose consciousness, then die. How to protect yourself from Hypothermia: Avoid situations that promote the loss of body heat. Keep dry and stay out of the wind. If you fall overboard, get out of the water as quickly as possible. Wear the proper clothing. Different materials offer different levels of insulation. For example, synthetic fibers offer excellent insulation from the wind, they do not protect the wearer for long when they are wet. On the other hand, wool insulates the wearer better from the effects of hypothermia while both dry and wet. Increase your energy reserve. Have a good meal prior to going out on the water. This way, your body will have something to draw on in case of an emergency. Avoid drinking alcohol prior to going out on the water. Besides the fact that mixing boats and booze is dangerous, illegal and downright dumb, there is a increased risk of hypothermia. Alcohol causes the blood vessels to dilate, which increases the amount of heat that is lost. This increases the effects of hypothermia if you get into an emergency situation
What to do in an emergency:
Get out of the water as soon as possible. If you can't get to shore or back on your vessel, DON'T SWIM! You'll lose more heat by swimming, than you will by treading water. In 70° water, a person can survive for 18 hours floating with a PFD, 13 hours treading water and only 10 hours swimming. In 55° water, the survival figures drop to 3 1/2 hours floating with a PFD, 3 hours treading water and only 2 hours swimming. In 35° water, they drop to 1 3/4 hours floating with a PFD, 1 1/4 hours treading water and only 3/4 hour swimming. Keep your clothes on. They'll provide insulation from heat loss. If you are wearing a life jacket, draw your knees up and make your body as compact as possible. This is called the HELP position. If there are two or more people in the water, huddle together to conserve warmth.If you are wearing a Type III life jacket, do not use the HELP position. You may turn face down. Instead keep your legs tightly together and keep your arms tight to your side. Lean your head back to keep your face out of the water. Keep your head out of the water. This is where you lose the majority of your body's heat. Get medical attention as soon as possible!