Cities across the United States and Canada must do more to prepare for the lethal convergence of extended power outages and lengthy heat waves, say experts on both sides of the border.

Christine B. Davis, of Humble, Texas (birthplace of Humble Oil, later Exxon) was 110 when she died this past summer. Cause of death was “environmental heat exposure due to power loss during/after Hurricane Beryl,” Houston Public Media reported, in a late August update on the death toll from the July storm.

At least eight other Texans, most of them over 60, died directly or indirectly from exposure to extreme heat in the hours and days after Hurricane Beryl made landfall, cutting power and leaving people baking inside homes where the mercury soared above 35℃ during the day and didn’t get much cooler at night.

In Houston and the surrounding area, 2.7 million people lost power pretty much instantly when Beryl hit. Hundreds of thousands remained without power for days afterward.

Clear and Present Danger

Many more lives could have been lost had the heat wave lingered as the days without power dragged on—a catastrophic possibility poised to hit some unfortunate Americans soon, said Prof. Brian Stone, director of the Urban Climate Lab at the Georgia Institute of Technology.

“I think it’s an absolute certainty that we will have an extreme heat wave and an extended blackout in the United States,” Stone said.

In the U.S., the Federal Emergency Management Agency (FEMA) defines extreme heat as “a long period (two to three days) of high heat and humidity with temperatures above 90°F.” Environment Canada defines it similarly: “a period with more than three consecutive days of maximum temperatures at or above 32°C/ 90°F.”

Recent modelling by the Post revealed how lethal a blackout could be if it coincided with an extended heat wave. Left without power for five days, “between 600 and 1,500 people in the Houston metro area” would die from exposure to heat. “With the power grid working normally, the same heat wave would lead to around 50 deaths.”

Houston, and the Southeast United States in general, are “particularly vulnerable,” the Post adds.

“All the ingredients for a monster heat wave and outage are already in place: an aging electricity grid, damaging hurricanes, and temperatures that break records every year.”

Exposure to extreme heat is hardly the sum of the dangers posed by the one-two punch of outage plus heat wave for the already vulnerable: medications spoil in the heat or become dangerous to take, medical devices like dialysis machines cannot run, and hospitals cannot get access to their increasingly digitized patient files.

Canada ‘Still Not Prepared’

The imperative to prepare for power outages during heat waves is very much on the radar of experts at the University of Waterloo’s Intact Centre on Climate Adaptation.

Two years ago, the Intact Centre’s report, Irreversible Extreme Heat: Protecting Canadians and Communities from a Lethal Future, urged municipalities to address the risks posed by the power outage + heat wave scenario—including the role of heat waves in causing power outages, whether from excessive demand or equipment failure.

Progress since then has been inconsistent, said Joanna Eyquem, the Intact Centre’s managing director of climate-resilient infrastructure.

“The National Adaptation Strategy has set several targets relating to extreme heat, which itself was a step forward to recognizing the seriousness of the threat,” she told The Energy Mix. The strategy pledges that:

• Two years from now, 80% of health regions will have implemented evidence-based heat adaptation measures.
• Six years from now, in 2030, public health systems will have identified risks, developed heat adaptation plans, and be actively measuring progress toward heat resilience.
• Sixteen years from now, in 2040, deaths from extreme heat in Canada will be a thing of the past.

However, “in terms of meeting these targets, we are still not prepared—the progress I have seen is patchy at best,” Eyquem said.

“One difficulty is that, with a lack of standards or coordination, responsibility is shared between electricity providers, governments, and individual building managers, [and] there is no requirement for adaptation reporting.”

And so far, there are “few examples of bylaws requiring backup power in multi-unit residential buildings, beyond the two hours required for evacuation purposes,” Eyquem said.

She cited the City of Toronto, with minimum guidelines that call for 72-hour backup power in multi-unit residential buildings in Waterfront Toronto’s Green Building Requirements [pdf].