Why CBC News is tracking indoor heat in 5 major Canadian cities

As the summer heats up, many people stay indoors to cool down. But for those who live without air conditioning, there’s little escape — even after the sun goes down.

That’s why CBC teams across the country are working together to track the heat, and the impacts on people when things go from hot, to sizzling, to seriously dangerous.

In dozens of homes across five major cities, CBC News installed temperature and humidity sensors to test exactly how hot it gets. Participants are sharing how they’re handling the heat — and how worried they are about staying safe, especially those living with children, seniors, and people with health conditions.

A heat sensor in a person's hand.
CBC News acquired 50 of these heat sensors that measure temperature and humidity, which were then installed in dozens of homes without air conditioning in five Canadian cities. (Tara Carman/CBC)

What are we tracking?

CBC News distributed 50 sensors in Vancouver, Winnipeg, Windsor, Ont., Toronto, and Montreal.

In each city, we reached out to people living without air conditioning. We installed the sensors in the homes of students and seniors, new Canadians and longtime tenants, and people living with chronic pain and other health conditions.

The devices measure the temperature and humidity in people’s homes every 10 minutes. Local CBC News teams then collect the data which we will use to compare indoor temperatures with outdoor temperatures in each city — like in the graph above showing the temperature in one Windsor, Ont., man’s home.

On particularly hot days, CBC News is also asking participants how the heat has been affecting them and what they’ve been doing to keep cool.

WATCH | Heat in Windsor home reaches 32 C at night:

Heat in Windsor home reaches 32 C at night

6 days ago

Duration 1:32

Elnaz Akhavan, who lives in a bachelor apartment in downtown Windsor without air conditioning, shows how hot it gets in her apartment, even after the sun goes down. She says the extreme heat makes it difficult for her to sleep and study at home.

Throughout the summer, we’ll speak with residents, experts, advocates and politicians to discuss the impacts of extreme heat and what should be done about it.

At the end of the project, we’ll share what we learned — what our data shows, the risk of persistent extreme heat indoors, and what some are doing to keep vulnerable populations safe.

Why does this matter?

The World Health Organization recommends that indoor temperatures remain under 32 C during the day and under 24 C at night. But many countries — including Canada — have no standardized legislation mandating a maximum temperature for indoor heat.

Meanwhile, Canada has already surpassed 1.5 C of warming over pre-industrial levels, with national temperature averages climbing by about 1.9 C from 1948 to 2021, according to Environment and Climate Change Canada.

The rising heat has already had deadly consequences — in 2021, the B.C. heat dome contributed to the deaths of 619 people, according to a report from B.C. Coroners Service. Many were seniors with compromised health, and those who died were twice as likely to be poor. More than two-thirds of people who died did not have air conditioning.

“We don’t let people freeze to death in winter,” said Ontario MPP Jessica Bell, who is also the provincial NDP critic for housing. “We shouldn’t be letting people die of heat stroke in summer.”

Creating guidelines for maximum indoor temperatures is an idea that is gaining traction, both at the municipal level and among advocacy groups. The City of Hamilton is in the process of drafting a bylaw that would require landlords to keep apartments below 26 C, the first of its kind in Canada. Grassroots group Climate Justice Toronto recently started a petition to the City of Toronto to implement a similar policy.

“Air conditioning should be a right for everyone. It is essential,” said Marcia Bryan, leader of the Peel branch of ACORN, an organization of low- and moderate-income people.

“I’m really glad that this data is going out there, so the politicians, government — everyone in power or authority — can see this and step up and do something,” said Bryan. “That [way] it’s not just tenants acting or nagging or complaining. There’s actually an issue going on, a bigger picture.”

More to this story? Send tips or stories to Lori.Ward@cbc.ca or Tara.Carman@cbc.ca.