Kiki Jones has spent the past few days taking cold showers, avoiding physical activity, keeping the blinds shut and blasting electric fans in their non-air-conditioned apartment in Toronto.

But despite those measures, the 31-year-old hasn't found much relief from the intense summer heat that's gripped the city this week.

“I've lived in Toronto for about seven years now and I haven't had A/C the entire time I've lived here, so it's definitely something that you come up with a lot of strategies to deal with,” said Jones, who uses gender-neutral pronouns.

“But, you know, once you reach a certain heat point, it becomes really hard to take care of yourself.”

Much of the province has been experiencing a stretch of scorching days this week, with temperatures topping 30 C.

For the approximately half a million Toronto residents who live in apartments without air conditioning, that's meant uncomfortable and potentially risky living conditions that experts say need to be addressed to protect against heat-related illnesses, particularly as extreme heat events are expected to become more frequent in the future.

Jones, who has asthma, said this week's prolonged heat made running errands particularly challenging when their home provided little respite from the hot conditions.

“I got home and I just felt so nauseous I couldn't really do anything else,” said Jones. “And you just get so physically exhausted.”

A recent report from the Intact Centre on Climate Adaptation at the University of Waterloo warns that extreme heat is growing more dangerous, driven by irreversible climate change.

It also notes that urban centres face the greatest risk because of the “urban heat island” effect, with surface daytime temperatures being 10 to 15 C hotter in certain urban areas where heat is retained in built-up regions, while nighttime temperatures can be up to 12 C hotter than in surrounding rural areas.

Blair Feltmate, head of the Intact Centre and co-author of the report, said people in urban centres who live in old highrise buildings with no central air conditioning are especially vulnerable in the face of extreme heat.

“This is a ticking time bomb, because just wait until we get to an extended heat wave with an electricity outage and these people are stuck in these buildings,” he said.

There are a host of ways that cities like Toronto can mitigate the impacts of and adapt to extreme heat, said Feltmate.

He suggested ensuring that apartments have “appropriate” backup electricity supply generation capacity, painting roofs of buildings white to reflect sunlight and having more tree canopy within cities to counter the heat island effect.

Feltmate also recommended subsidizing or providing people with cooling devices like window air conditioning units and fans for free so that those who cannot afford them can stay cool.

“I believe under the conditions of climate change, we should look at access to readily available cooling devices as a human right,” he said.

The City of Toronto said approximately 500,000 people live in apartments without air conditioning in the city.

It said it has developed programs to support building owners and operators with retrofitting windows, doors, cladding and other elements to reduce temperatures within units. And it noted its “heat relief network” of cool spaces throughout the city, including libraries, community centres, malls and pools, can help residents seeking to beat the heat.

“Part of the City of Toronto's long-term strategy for dealing with extreme heat events ... is around the improvement of the City's older apartment stock that does not have air conditioning in units, mostly rental units housing approximately 500,000,” it said.

Dr. Anna Gunz, a pediatric intensive care doctor at the Children's Hospital in London, Ont., and associate professor at Western University, said extreme heat needs to be treated seriously.

“The climate crisis and the air pollution crisis is a health crisis,” she said.

Extreme heat can have numerous impacts on health, including heat exhaustion, heat strokes and death, said Dr. Samantha Green, a family physician at St. Michael's Hospital and faculty lead in climate change and health at the department of family and community medicine at the University of Toronto.

It can also exacerbate underlying health conditions like mental illnesses and heart disease, she added.

People who are most vulnerable are the elderly, those with chronic health conditions, infants, pregnant women, as well as those who don't have access to resources to cope with extreme heat, including low-income residents who don't have air conditioning.

Green said ways to tackle the issue include planting more trees to provide tree cover that can help with cooling and ensuring new buildings and building retrofits are done in a way that allows for passive cooling.

“The climate emergency is here,” she said. “Ten years ago would have been the best time to intervene, but now is the second best time to intervene.”

This report by The Canadian Press was first published July 22, 2022.