On a warm Monday morning in June, Kamloops, B.C. experiences overcast skies with temperatures around 20 C.
Despite the comfortable air temperature, Teresa Seibel is testing the water temperature at Little Heffley Lake, located approximately 30 kilometers northeast of the city.
The water thermometer indicates a temperature of 19.3 C — suitable for swimming.
Seibel has recently completed a swim across the English Channel, where water temperatures can drop to as low as 5 C.
In the months leading up to her swim, she adapted her body to colder waters, utilizing her swimming pool in chilly conditions to avoid a potentially dangerous situation known as cold water shock.
Teresa Seibel is an experienced swimmer who understands the dangers of swimming in frigid waters. (Shelley Joyce/CBC)
Brian Twaites, a public information officer and paramedic with B.C. Emergency Health Services, explains that cold water shock can occur when an individual suddenly enters water that is below 15 C.
“This isn’t about simply walking into cold water,” he clarified. “It involves jumping or falling into cold water from a boat or dock.”
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Recognizing Cold Water Shock
With British Columbia containing numerous cold lakes, streams, and ocean waters, Twaites emphasized the importance of recognizing the signs of cold water shock and knowing how to prevent it.
Upon entering icy waters, the body triggers a fight or flight response, resulting in a gasp reflex that can lead to involuntary inhalation. If submerged, Twaites warned, individuals might inhale water.
Following this, the body may hyperventilate, leading to rapid and uncontrollable breathing. This reaction increases heart rate and blood pressure, placing additional stress on the cardiovascular system.
B.C. Emergency Health Services warns individuals venturing outdoors about the dangers of ‘cold water shock,’ which can occur within moments of jumping or falling into a frigid B.C. lake or river and could be lethal.
“You also experience cold incapacitation, where strength and coordination in your arms and legs diminish quickly after being submerged in cold water,” Twaites explained.
“All of these reactions can lead to panic, impairing your ability to make sound decisions.”
He pointed out that cold shock differs from hypothermia, as cold water shock can be fatal before hypothermia, which develops after extended exposure to cold conditions, has a chance to set in.
Staying Safe in Cold Water
Twaites mentioned that cold water shock could contribute to numerous drownings in British Columbia. To date, at least 20 individuals have drowned in B.C. waters this year. Additionally, six people are presumed drowned following a boat capsizing incident near Richmond on June 28.
To minimize the adverse effects of cold water shock, he advised wearing a life jacket, keeping your head above water, and striving to remain calm.
“Focus on regulating your breathing,” he emphasized.
“Surprisingly, we don’t recommend immediately attempting to swim. Instead, concentrate on controlling your breath… conserve energy until you have gained control of those aspects.”
