Extreme heat days are overheating schools more often — and experts say it needs our attention

As summer approaches, classrooms start getting sticky and uncomfortable, according to Grade 8 students at Sts. Cosmas and Damian Catholic School in Toronto. 

“You’re always sweating a lot and you’re always focusing on: ‘Oh my God, I want to cool down,'” said 13-year-old Carmine Pantano. “I can feel a little bit dizzy when it’s too hot.”

On hot days, shades come down, windows capable of opening are, lights go off and the library becomes a cooling centre booked in 20-minute increments. Tower fans whir from classroom corners. Built in the 1950s, the school doesn’t have air conditioning.

This year, there is an outdoor misting station to provide some cooling, one of 12 being piloted by the Toronto Catholic School Board. It helps, especially after gym class, the kids say, but the relief is temporary.

“It’s a solution, but not exactly for the problem we have. It doesn’t solve the heat in the classrooms,” noted Grade 8 student Cameron Santicruz.

As extreme heat becomes more common due to human-caused climate change, so are overheated classrooms — causing problems in late spring and into September. In some regions, extreme heat also comes with concerns about smoke from wildfires.

Parents, educators and experts are calling for more attention and investment to ensure Canadian students have cool, clean-air environments to learn in.

“Really, there is no area in Canada that will avoid extreme heat,” said Caroline Metz, managing director of climate resilience and health at the University of Waterloo’s Intact Centre on Climate Adaptation.

“It’s prevalent across the country. The risk is great now and also moving forward into the future. And I think indoor overheating is especially a concern for homes and schools.” 

Overheating a serious concern

After 2023 marked the hottest year on record, this summer may be another record-breaker. Yet, Metz says many still underestimate the hazards of heat.

“It’s responsible for more illnesses and deaths than all other natural weather hazards,” she said from Waterloo, Ont.

Generally, indoor temperature should sit below 26 degrees Celsius, Metz said. Between 26 and 31 degrees, there’s a greater risk of health impacts. Being inside at above 31 degrees Celsius for a sustained period “can be dangerous for everyone.”

The concern goes beyond being uncomfortable or sweaty in class.

Children’s higher metabolism means “their demand for cooling off is going to be higher” than adults, said Eric Coker, a senior scientist for the B.C. Centre for Disease Control (BCCDC). 

Furthermore, children are less likely to notice if they’re experiencing signs of heat-related illness.

Subtle ones like feeling agitated, being thirstier than normal or taking fewer washroom breaks can lead to more serious signs, including dizziness, weakness, leg or stomach cramps, confusion, nausea, vomiting and diarrhea. 

“They want to play with their friends and … [are] unaware that they are having these more subtle signs of dehydration. The greater exposure to the heat is just going to put them at higher risk,” Coker explained, adding that hot temperatures can also affect students’ learning performance.

If a region is grappling with poor air quality due to wildfire smoke as well, there are different symptoms to watch out for in kids, such as dizziness, sore throat, eye irritation, runny nose, cough, wheezing or difficulty breathing. 

Schools need to have a plan in place to deal with both heat emergencies and wildfires, Coker said, since scientists expect both to grow in frequency, intensity and also overlap seasonally.

“Schools need to be ratcheting up the resilience to environmental conditions that are clearly being impacted by climate change.”

A school board responsibility, say ministries

CBC News reached out to Canada’s 13 provincial and territorial education ministries to ask how they’re supporting school boards, districts and divisions in addressing climate-related extreme heat or wildfire smoke. 

British Columbia, Prince Edward Island and Nova Scotia noted their ongoing investments into improving school ventilation systems.

However, with no air conditioning in most Nova Scotia schools, during extreme heat, many facilities instead rely on using fans, opening windows or holding class in shaded outdoor areas or other cooler spaces, said Alex Burke, director of communications for the province’s department of education.

Yukon and Northwest Territories highlighted their requirements for boards to regularly update school emergency response plans, which may cover extreme weather events.

B.C. — hit hard in 2021 by deadly weather events like the heat dome, a severe wildfire season and intense flooding followed in 2023 by another round of record-breaking wildfires — noted its work with the BCCDC to create guidance for schoolchildren relating to wildfire smoke exposure. The province says it’s also weaving climate resiliency into school construction projects, including by installing heat pumps in most new builds.

Quebec, Manitoba, New Brunswick and Nunavut did not respond by the deadline; Ontario shared a memo listing ventilation improvements and guidance sent to school boards in September 2023. 

Of the eight regions that did respond, including Newfoundland and Labrador and Saskatchewan, most described the overall issue as a school board responsibility — to be paid for from the existing funding they receive.

“School boards have the autonomy, accountability, and responsibility to ensure their facilities meet regulatory requirements and to ensure programming and operations are responsive to extreme weather conditions to ensure students are best supported,” Kevin Lee, press secretary to Alberta Education Minister Demetrios Nicolaides, said in a statement.

However, with so many schools dating from Canada’s mid-century boom between 1950 and 1970, there isn’t enough money to put air conditioning in every school that needs it and tackle the backlog of other maintenance, said Maria Rizzo, a longtime trustee for the Toronto Catholic District School Board (TCDSB). 

It’s not feasible to “retrofit air conditioning for [an older] school — it’s too expensive…. We have to replace roofs, we have to replace boilers, we have to replace windows. We have to do all of the maintenance that needs to be done” from the same budget, she said.

“The money that the [Ontario] government gives us isn’t enough.” 

Rizzo, who pitched the Catholic board’s current misting stations pilot, wants to see dedicated funding for air conditioning. 

This must be considered as a safety issue, says Sara Concordia, whose daughter attends a multi-storey TCDSB school struggling with cooling. 

Her daughter, who’s in Grade 4, has regularly come home cranky and tired, noting that a thermometer in her classroom often rises to 27, 28, 29 or 30 degrees Celsius — which can feel even higher when humidity is a factor, Concordia added.

“We should not put expense above our children’s health and safety,” she said. 

Passive cooling options

While air conditioning is what’s needed for the most at-risk populations, says Metz, the climate adaptation expert, schools should consider passive cooling, which is less costly and more sustainable.

These strategies can include:

• Painting school roofs white to repel the sun’s rays (versus dark roofs that attract them).

• Opening windows, including at night to bring in cooler air.

• Installing sun-blocking shades or curtains inside and window coverings like awnings or shutters outside. 

• Planting more shade trees and other greenery or vegetation around schools to help cool the building and surrounding areas, take in carbon dioxide from the atmosphere and help absorb rainwater during heavy rainstorms.

During instances of extreme heat, high use of air conditioners can strain power grids, whereas passive cooling strategies even work during an outage, she said.

Metz feels schools are in a perfect position to teach students about climate challenges as they tackle the issue themselves. 

“Schools could launch an education campaign on extreme weather risk — including extreme heat — and then highlight the solutions that would help ensure people are safe in their indoor spaces,” she said.

Check the CBC News Climate Dashboard for live updates on wildfire smoke and active fires across the country. Set your location for information on air quality and to find out how today’s temperatures compare to historical trends.