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It’s a warm Monday morning in June in Kamloops, B.C. The sky is overcast and the temperature is hovering around 20 C.
Though the air is warm, Teresa Seibel is checking the temperature of the water at Little Heffley Lake, about 30 kilometres northeast of the city.
The thermometer reads 19.3 C — safe to swim.
Siebel has just returned from swimming the English Channel, where the temperature can fall as low as 5 C.
She spent the months prior acclimatizing her body to cold water, using her swimming pool in frigid temperatures, hoping to prevent a potentially life-threatening situation known as cold water shock.
According to Brian Twaites, a B.C. Emergency Health Services public information officer and paramedic, cold water shock can happen when your body is suddenly immersed in water below 15 C.
“We’re not talking about walking into cold water,” he said. “We’re talking about jumping into cold water or falling into cold water off of a boat or a dock.”
What does cold water shock look like?
Given that B.C. is home to hundreds of cold lakes, streams and ocean waters, Twaites said, it’s important to know the signs of cold water shock, and how best to prevent it.
When you fall into icy water, the body reacts by going into a fight or flight response, Twaites said. And the first thing that happens is a gasp reflex, leading to sudden inhalation. If you’re underwater, he said, you could inhale water.
Then, he said, the body begins to hyperventilate, causing breathing to become fast and uncontrollable. This in turn increases heart rate and blood pressure, increasing strain on the cardiovascular system.
B.C. Emergency Health Services has a warning for people heading out into the great outdoors. It’s around a condition called ‘cold water shock,’ which can happen within minutes of jumping or falling into an icy B.C. lake or river, and can be fatal.
“You also get this cold incapacitation, where you’re in the cold water and you’re going to lose strength and coordination in your arms and legs within minutes of being submerged,” Twaites said.
“All of this, of course, gives you a panic response which is going to impair your decision-making.”
Cold shock is different from hypothermia, he said, in that cold water shock can be fatal before hypothermia — which happens after a longer period in a cold environment — even sets in.
What can you do to stay safe?
Twaites said cold water shock could be a contributing factor to many drownings in British Columbia. So far this year, at least 20 people have drowned in B.C. waters. Six people are also presumed drowned after a boat capsized near Richmond on June 28.
He said the best way to prevent the negative effects of cold water shock is to wear a life-jacket, keep your head above water and try to remain calm.
“We want you to focus on controlling your breathing,” he said.
“Believe it or not, we don’t want you to try and swim right away. We want you to get control of that breathing … don’t use excess energy until you have those things under control.”
