Who’s at risk during B.C.’s first heat wave of 2025

A special weather statement is in effect for much of southern B.C., where warmer temperatures are in the forecast.

While most of us will be enjoying the first heat wave of the year, health officials are warning that some British Columbians should watch for signs of trouble.

Several health authorities published bulletins on Friday to urge the public to prepare for temperatures forecast to be in the mid-to-high twenties this weekend with plans to keep cool and hydrated.

“Though we haven’t reached the criteria for a heat warning or an extreme heat emergency, there is some concern that people, especially those at higher risk, might be at increased risk,” said Dr. Michael Schwandt, a medical health officer with Vancouver Coastal Health.

For example, seniors, young children and babies, those who are pregnant, diabetics, have heart or respiratory disease, have substance use disorder, have disabilities or cognitive impairments, and those living alone are at increased risk. Certain medications, like anti-psychotics and anti-depressants, as well as diuretics can make people more vulnerable.

Anyone who’s had heat stroke in the past is likely to have sensitivity to higher temperatures.

Early season heat is different

Though the temperatures will be significantly lower than the rare 2021 heat dome event, which saw 619 British Columbians die in record-shattering heat, this weekend’s heat wave is still early in the year to see temperatures like those forecasted.

“Temperatures that might, by the end of the summer, not present much of a challenge can actually have a greater health impact early on in the summer,” explained Schwandt. “This is because our bodies—although we can become acclimated to extreme heat quite quickly, actually in a matter of weeks—just haven’t had that opportunity as we move from spring to summer.”

The B.C. Centre for Disease Control says, “Severe headache, confusion, unsteadiness, loss of thirst, nausea/vomiting, and dark urine or no urine are signs of dangerous heat-related illness.”

SFU researchers urge long-term planning

As public health leaders and municipalities urge people to take steps to respond to the heat on the horizon, researchers at Simon Fraser University want them to think about mitigating the risks for years to come with concrete action in the near-term.

Associate professor in urban planning, Andreanne Doyon, analyzed more than 240 documents with her co-author and concluded there are gaps in planning for future events like the fatal heat dome of 2021, without a government agency – or even level of government – responsible for quarterbacking future planning.

“Every summer we’re going to experience this, and our buildings and our neighborhoods have never been built with heat in mind because we’re temperate place,” she said.

While the BC Building Code was updated last year to include maximum acceptable temperatures for new home construction, retrofitting older buildings with air conditioning and the requisite power upgrades, or replacing windows and insulation are much more complicated and less feasible. Concrete jungles without tree canopy or shady areas were also identified as factors that built “heat islands” and contributed to the death toll.

“I want people planning for heat in February, not July,” said Doyon. “It should be something that we’re always prepared for and always thinking about.”