Britain recorded its hottest-ever temperature Tuesday as Europe continues to swelter under a heat wave that has sparked mass wildfires, killed hundreds of people and displaced thousands across the continent.

The temperature at London’s Heathrow Airport was a sizzling 40.2 C in the early afternoon, marking the first time on record the U.K. has seen a temperature above 40 C. Toronto hasn’t been that hot since 1936 — though the city was under its own heat warning Tuesday, reaching 34 C — but accelerating climate change means higher temperatures are on the horizon for us, too. Are we ready?

While Toronto is better equipped than Britain to deal with heat waves, experts say, the city is unprepared to weather such lethal heat.

Most often, when talking about climate change, people focus on floods and wildfires, says Blair Feltmate, head of the University of Waterloo’s Intact Centre on Climate Adaptation.

But while those weather events cause damage to infrastructure and the environment, extreme heat is in “a whole other category,” Feltmate says.

“With extreme heat, when things go wrong, people can die in the hundreds and if not into the thousands.”

The U.K. government issued its first-ever red warning for extreme heat. It was so hot at Luton Airport on Monday night that part of the runway lifted into the air, forcing a suspension of flights.

Meanwhile, raging fires in Portugal, Spain, France and other southern European countries have forced tens of thousands of people to evacuate. More than 1,100 people in Spain and Portugal have died from heat-related causes in the past week, the countries’ health ministries said, with tolls expected to climb.

Unlike the United Kingdom, where houses were built to retain heat and air conditioning is rare, most Torontonians have access to cool air — if not at home, then in shopping malls, public libraries and cooling centres. But experiences in other provinces show that’s not always enough to beat the heat.

A heat dome in B.C. in 2021 claimed more than 600 lives, after temperatures surpassed 40 C for several days in late June and July. Most of the people who died were elderly, with pre-existing conditions, and lacked air conditioning, according to an investigation by the coroner. In 2018, 86 people in Quebec died from a heat wave. In both of those cases, electricity was up and running and air conditioning was available. The worst is likely still to come.

“The extreme heat that we’re experiencing today pales in comparison to the extreme heat events that are coming in the future,” Feltmate said.

The United Nations climate body has warned that extreme-weather events, including heat waves, will become more frequent as the climate crisis accelerates.

Canada is already hot, and it’s getting hotter. An April 2022 report from Waterloo’s Intact Centre, which Feltmate co-wrote, warned extreme heat coming for Canadian cities in the coming decades will pose major risks to human health, infrastructure, wildlife and plants.

The study projects metropolitan areas, including Toronto, will see hotter days — more of them, and for more prolonged stretches — as world greenhouse gas emissions continue to increase. Between 2051 and 2080, so long as emissions continue, Toronto could see an average of 55 days a year above 30 C, compared to just over 10 between 1976 and 2005.

And this doesn’t take into account the urban heat island effect, which can cause temperatures in urban centres to be about 10-15 degrees hotter than surrounding rural areas, since pavement and buildings retain more heat.

A look back in time offers a harrowing glimpse of Toronto under 40 C. On July 9, 1936, in the middle of an eight-day hot spell that killed more than 275 people, the mercury hit 40.6 C — the highest temperature ever recorded in the city.

The Toronto Daily Star (the Star’s name at the time) wrote of the anguish of kids living in the city’s downtown core — or “districts of torture.”

“Living in houses that are sweltering hot boxes, tossing in beds, listlessly, lifelessly seeking a place to cool their feverish bodies, a great mass of the children of the poverty-stricken districts of Toronto are today experiencing some of the horrors of Dante’s Inferno.”

The city imposed a watering ban after residents left their hoses on all night trying to keep cool, leaving East York without water. “You could fry eggs on the street car rails,” wrote the paper.

While technology and infrastructure have advanced since the 30s, a similar heat wave could still cause mass suffering today, Feltmate said.

As with the deadly waves in B.C. and Quebec, extreme heat disproportionately harms vulnerable people, including the elderly, people who are homeless or precariously housed, and those with pre-existing conditions.

In Toronto, about half a million people live in older apartment buildings that tend to be eight storeys or higher, and lack central air, Feltmate said. One-third of those buildings do not have backup power to run elevators beyond about two hours. That means if a heat wave were to coincide with an electrical outage, those people, especially if they can’t easily get down stairs, “could very easily find themselves in harm’s way.”

Chris Chen, executive director of Asset Management Ontario, a non-profit that advises municipalities on infrastructure with a focus on the environment and climate change, said while Toronto is not the worst-prepared city with regards to handling extreme heat, there is work to be done.

Toronto has good short-term heat response measures in place, Chen said, gained through “hard experience” with heat waves. Each summer it enacts a heat response plan that includes extending hours at outdoor pools, publishing a map of more than 300 public “cool spaces” and opening emergency cooling centres. People can also benefit from the low-income energy assistance program, which provides air conditioning grants.

But long term, as the city and planet warm, Toronto must re-examine the way it is built in order to survive.

Essentially, Toronto needs more trees, smaller windows and better air conditioning access.

“I know people like windows — and who wouldn’t?” said Chen. “But we know a smaller window-to-wall ratio helps mitigate heat within buildings. Countries that experience a lot of heat, their buildings tend to have smaller windows.”

Toronto, meanwhile, has scores of glass towers with floor-to-ceiling windows, providing little reprieve from the sun.

“Either we really improve the technology for windows or we start to address size.”

Growing green spaces, and investing in their upkeep, also improves a city’s defence against heat. Tree canopies create shade that makes the heat more bearable.

“Places with more greenery, more trees, mitigate the relentlessness of the heat,” said Chen. “It’s also a social equity issue, ensuring all people have access to it.”

Research indicates people of lower socio-economic status have less green space near their home. A 2020 study published in Environment International found 38 per cent of Torontonians live in areas with little greenness.

Heat can be deadly, Chen said, and some of the most at-risk people are those without air conditioning. In response, University-Rosedale MPP Jessica Bell put forward a motion that would mandate climate control in buildings.

Chen said while this could save lives, there are factors that would make it difficult to implement in Toronto. The New Democrat’s motion would make the maximum allowable temperature in homes 26 C.

“It would drive change, but it’s hard to enforce, it could stress the power grid and it would probably increase rental costs significantly, and Toronto already has affordability issues,” said Chen. “The city would have to address those issues. But it would be great, from a public health perspective, if homes stayed between 21 and 26 C.”

Lex Harvey is a Toronto-based politics reporter for the Star. Follow her on Twitter: @lexharvs

Ben Cohen is a Toronto-based staff reporter for the Star. Follow him on Twitter: @bcohenn