|Kayakers have been found dead hanging upside down in their kayaks, having apparently made no attempt to even exit their boats. Most kayak deaths are listed as drownings. It was thought that these victims drowned because of hypothermia. Recent speculation is that many of these drowning victims may actually be victims of Cold Shock, a sudden and deadly result of a quick plunge into cold water.
Plunging your torso, head and neck into cold water (<50 degrees F <10 degrees C) can lead to a number of catastrophic debilitating physical reactions that can lead to immediate death. The colder the water, the more likely cold shock may affect you. Without a PFD on when you go over, you will not survive if cold shock occurs. Many PFDs typically worn by kayak paddlers will not save you either.
When your body is quickly immersed in cold water, it reacts with a sudden constriction of the capillaries under the fat just under your skin. This causes a sudden increase in blood pressure. Your heart rate rises dramatically, perhaps to its maximum. These are automatic physical reactions and can not be consciously controlled. The following can happen:
- Immediate loss of consciousness. Without a PFD that will right your body and float your nose and mouth out of the water, or immediate assistance, you will drown. Most PFDs worn by paddlers (Class III or Class V ) will not right an unconscious body.
- Cardiac arrest from the strain placed on your heart. If your heart can not stand the sudden jump to maximum heart rate and the high blood pressure, it stops. Without immediate assistance, you are dead.
- Involuntary Gasping Reflex can cause you to inhale while you are underwater. You will not be able to prevent this reflex reaction. Cold water in the lungs or muscle contractions of the windpipe may prevent you from breathing should you regain the surface. If you hit your roll or wet exit wearing your PFD, you PFD will bring you back or keep you at the surface. Perhaps you live. No PFD, straight to the bottom with you.
- After gasping in a lung full of cold water, the temperature of you heart plunges, the muscles stop contracting and you die. Even if you manage to gain the surface or even land, you may still die if you can not empty your lungs quickly enough.
So how do you prevent cold shock?
- Only paddle in warm water. Not a realistic option for most paddlers.
- Wear protective clothing - a neoprene wet suit or dry suit will protect the torso from the immediate effects of the cold water and reduce the possibility of cold shock. However, most paddlers still leave the head and neck areas exposed. Wearing a neoprene hood that covers the neck and head will greatly reduce the possibility of cold shock.
- Practice - immerse yourself in cold water in safe conditions with someone to rescue you if you need it. Tolerance can be built up. However, you can never be sure how your body will react each time, particularly regarding cardiac arrest. Practice can be dangerous in and of itself. Make sure that your rescuer knows what needs to be done if you fall victim to cold shock. Start small by taking cool showers and progress to cold showers. Consult your physician before attempting any of this.
When the water is cold, never paddle by yourself. If you are a cold shock victim while paddling alone you will die.
Remember it is the temperature of the WATER, not the air that matters. In fact if the air is warm while the water is cold, the possibility of cold shock is even higher as the warm skin and dilated capillaries are plunged into cold water. The greater the difference between air and water temperatures, the more likely cold shock will occur. Spring is the most likely season for Cold Shock accidents as the warm air temperatures encourage kayakers to dress for the air temperature and not the water temperature.
The more fit your are, with a lower body fat content, the more susceptible you are to cold shock.