By Alan Wade
http://stream.publicbroadcasting.net/production/mp3/wkms/local-wkms-960991.mp3
Kuttawa, Ky – Our waterways hold danger in cold weather. Alan Wade is a member of the U.S. Coast Guard Auxiliary, and next he reviews facts about hypothermia, cold shock, and tips to remember before setting out when it's cold.
On the lakes and rivers of Western Kentucky, from early October until the following May, the crowds of boaters present during the regular season disappear and boaters can enjoy relatively undisturbed time on the water. But, along with the advantages of being on the water in the off-season, there are some definite disadvantages. One of these is the danger of exposure to cold water (less than 60 deg F). Accidental immersion in cold water can quickly become a life-threatening situation, particularly at a time when the likelihood of rapid rescue is reduced.
The development of hypothermia (decreased body temperature) is only one of several effects on the body of exposure to cold. Heat loss from the body occurs 25 times faster in water than it does in air and, most of that loss is through the head. However, in cold water immersion, most people die, not from hypothermia, but from drowning. Immediately after exposure to cold water, a victim will usually experience an involuntary gasping reflex, a symptom of what is called cold shock. If not wearing a life jacket, the victim may inhale while under water and drown before making it back to the surface.
Cold shock also causes other, immediate effects on the lungs and heart, including an inability to hold your breath, and increased heart rate and blood pressure, which could lead to cardiac arrest. Also, diversion of blood flow from peripheral areas into the core of the body, along with cold temperature, can reduce the ability of the muscles to contract. There is a loss of coordination in the arms and legs, making swimming difficult. If a victim tries to swim, the muscles fatigue rapidly and heat loss increases.
Hypothermia develops more slowly than the immediate effects of cold water immersion. If a person is wearing a life jacket, it is possible for them to survive for several hours in the water at temperatures below 60 deg. Survival time also depends on the type of clothing they are wearing, keeping physical activity to a minimum, and using a posture in the water that conserves body heat. Even after rescue, in severe hypothermia, the person should be kept warm, on their back, immobile, and handled gently. Arms and legs should not be stimulated since cold blood from the extremities could suddenly return to core areas and cause cardiac arrest. Seek medical help immediately.
Surviving an accident on the water in cold weather depends on planning ahead. Most importantly, wear a life jacket at all times. Also, wear clothing that is best at preventing heat loss in the water, preferably, under a waterproof outer shell, like a wetsuit and, keep the head covered. If you go into the water, try to get back in or on the boat. Always stay with the boat and avoid trying to swim to shore. Have signaling devices like a whistle and flasher attached to your life jacket. Be sure to let someone know where you are going, when you will return and, if you did return, and check existing weather conditions. Being aware of the precautions to take will allow you to stay safe and enjoy activities on the water anytime during the year.
Alan Wade is a member of the U.S. Coast Guard Auxiliary, a volunteer branch working to contribute to the safety and security of our citizens, ports, waterways and coastal regions.