Summer has arrived and for many that means time on the water. Although the air temperature may be hot, the water is still very cold and dangerous if you fall in. Cold-water shock can be very dangerous. The shock to the body from entering water that is 15C or below is often underestimated and very scary. The shock will affect your breathing and your ability to move, leaving you susceptible to hypothermia and potentially drowning.
Cold-water shock causes the blood vessels in the skin to close which limits blood flow. Your heart rate will increase due to the shock. This results in your heart needing to work harder to keep the blood flowing which will cause an increase in your blood pressure. This increase in blood pressure could cause a heart attack even in a healthy, young person.
The sudden exposure to the cold causes an involuntary gasp for breath. Breathing rates will increase uncontrollably sometimes increasing as much as tenfold. These combined feelings of your increased heart rate and breathing will cause a sense of panic, increasing the chance of inhaling water directly into your lungs. All this can happen very quickly and with dire consequences.
There are some ways to help minimize the impacts and risk. If you enter the cold water unexpectedly, take a minute. The initial effects will ease up within a minute. Relax and float on your back to catch your breath. Try to hold on to something to help you float. Stay calm and call for help or if you are able to swim to safety.
Before you go out on the water always check conditions including water temperature, wind, and weather. If the water is cold wear a wetsuit. Always remember to wear a personal floatation device (life jacket)
