As the ground changes from white to brown to green and more and more sunshine fills the sky between the clouds, you know it’s finally spring in Teton Valley. The sun sure feels warm enough; time to dust off that boat, raft, or kayak and head for the river, right? Sounds like a good plan to me, but remember that the water you’ll be floating in was ice and snow yesterday.
Splashing into the cool water on a hot day is part of the fun of boating for some strong swimmers. But if that water is too cold, as it is this time of year, it doesn’t matter if you are a good swimmer or not. Cold water is deadly.
Cold water shock has a dramatic impact on your body. Your blood pressure and heart rate skyrocket, and you lose muscle control, including breath control. Automatic and uncontrollable gasping can result, and this, of course, is almost instantly fatal if your head is underwater. Then, even if you avoid that fate, the loss of muscle control and uncontrollable shivering will take their toll on your ability to swim or tread water. This is why wearing a life vest is always a good idea on the water, even if you know how to swim.
So, how cold is too cold? Don’t compare water temperature to air temperature. A 50-degree F day may be perfectly comfortable to you, but according to the National Center for Cold Water Safety, 50 to 60-degree water is deadly and causes most people to lose breathing control completely. Even in a wet suit or dry suit, cold water still feels painful on your face and uncovered extremities. The rule for Olympic swimming competition is that the water must be above 77 degrees. Below that, people have progressively more trouble controlling their breathing until they reach immediately life-threatening total loss of control in the 50-degree range.
If you survive the immediate shock of falling into cold water, maybe you have on a life vest or grab onto the side of the boat to stay afloat, you then face the issue of hypothermia setting in. It will make you unresponsive if you don’t get out of the cold, dry off, and warm up fast. How long you have depends on how cold the water is and, to some extent, the person. But remember, when the Titanic sank, no one who didn’t make it into a lifeboat lived to tell the tale. Even strong athletes and good swimmers in life vests did not survive the cold water when the great ship went down.