Officials updating B.C. extreme heat plans annually after heat dome tragedy

It was four years ago this week that morgues were overrun by hundreds of unexpected deaths during the 2021 heat dome.

Officials from various provincial agencies are now updating British Columbia’s preparations and plans to respond to extreme events annually, CTV News has learned.

The B.C. Centre for Disease Control, Ministry of Health, and Environment and Climate Change Canada co-author the B.C. Provincial Heat Alert and Response System (BC HARS) and are revising response plans in the wake of the 2021 heat dome that saw 619 people die as a result of exceptionally high temperatures.

In fact, one of the revisions was the death toll, initially finalized at 595 by the B.C. Coroners Service and later updated to 619.

“We had some people reporting temperatures in the 50s (Celsius) in their homes, and so since then we’ve had that real focus on indoor temperatures,” explained Sarah Henderson, the BCCDC’s scientific director of environmental health services.

The first HARS plan was assembled in 2022 and has seen revisions since then as stakeholders have contributed new strategies, observations, and issues that need addressing.

Henderson acknowledged that the province’s pre-2021 hot weather response plan was based on a heat wave in 2009 that killed more than 100 British Columbians, but since those deaths were predominantly located in the Lower Mainland, the new B.C. HARS plan is based on province-wide metrics.

For example, average temperatures must be above what’s normal for certain sections of the province for more than two days before measures are taken. The current HARS decision algorithm takes that into account, and lays out detailed expectations for first responders, hospitals and local governments during both heat warnings and more severe “heat emergencies.”

Such measures can include extending operating hours for air-conditioned community centres and making drinking water available in hospital waiting areas, for example.

Under a heat warning, the document anticipates a five per cent increase in deaths, but in an extreme heat emergency, it warns there could be 20 per cent or more than usual. According to internal documents obtained by CTV News, in the immediate aftermath of the 2021 heat dome, experts had anticipated a 20 per cent increase in deaths in extreme heat, but instead there were 15 times more than expected.

Despite the new protocols and guidance document, 11 people died from heat-related injuries in 2023. Some doctors have suggested that there’s now extra vigilance for hyperthermia and that previous years were likely under-reported.

As for whether B.C. is now prepared for another week-long stretch of exceptionally high temperatures, Henderson is reluctant to make predictions.

“We’re much readier. Are we as ready as we need to be? Likely not,” she said. “We often talk about the 2021 heat dome as unprecedented. That doesn’t mean that something else, even more unprecedented won’t come along.”

• Related: Four years after horrific B.C. heat dome, improvements, enduring risks, and no plans for a memorial