With extreme heat, schools struggle to provide students with optimal learning environment
Alexis Wright/The Pointer

With extreme heat, schools struggle to provide students with optimal learning environment

The northern hemisphere is entering the final weeks of its hottest summer ever, with many looking forward to relief as fall nears. But while stores are already selling Halloween candies, signalling the arrival of autumn weather, temperatures remained in the 30s throughout much of the week, with oppressive humidex values reaching the low 40s. 

Last month was the hottest August scientists have ever recorded (with modern equipment) by a large margin. September rolled in with temperatures that were even higher, as students across the GTA had to settle into sweltering classrooms. 

Not only are our summers getting warmer, the hot weather is arriving earlier and staying late, a trend that will continue to creep in. For an education system designed to operate throughout the coolest months of the year — with a break from late June through August — many schools are not equipped to optimize student learning in extreme heat, which will become more and more common.

Caledon resident Sakina Rehmanji told The Pointer her son, who has a degenerative neuromuscular disease, can struggle in the extreme heat and has to stay hydrated in class to help avoid adverse symptoms. Other parents expressed frustration that at Robert F. Hall in Caledon East, a high school in the Dufferin Peel Catholic District School Board (DPCDSB), the air conditioning system was not functioning properly on the first day of school, Tuesday, when temperatures reached 33-degrees celsius, according to Environment Canada, with a humidex value of 41 degrees. The overwhelming temperatures, made worse by classes filled with up to 30 students, were described by Jennifer Gatt’s son as “unbearable”. She chose to keep him home Wednesday, fearing the school’s AC system still would not be fixed — a good call, as the humidex value was slightly hotter than the day before.

The scorching temperatures make it difficult for students to learn.

A 2018 study from Harvard medical school evaluated the impact that heat has on cognitive function and learning in students living in college dorm rooms by comparing the results on basic tests between students whose rooms were at 71 degrees Fahrenheit (21.7 degrees Celsius) and those whose rooms were kept at 80 degrees Fahrenheit (26.7 degrees Celsius). Those students with cooler rooms could maintain that temperature with air conditioning while the latter group was simulating students living without access to air conditioning.

Over a two week period, the two groups of students were asked to complete basic tests on their phone that consisted of simple addition and subtraction and tests involving a mixture of colours and words. Those who were living in higher temperatures displayed lower performance levels on all tests provided.

There are two major reasons for these results, said Dr. Stephen Cheung, a professor and senior research fellow in the Department of Kinesiology at Brock University in St. Catharines. Scientists know the hotter the body gets, blood flow to the brain decreases. When our bodies heat up, Cheung said, there is an increase in blood flowing outward to our skin in order to get rid of heat. This change in blood flow through the body can reduce the amount of flow to the brain, altering its function. 

“When there's less blood flow going to the brain, that changes the electrical activity of the brain, and some signals suggest that there is less arousal,” Cheung said. As the brain decreases its arousal, it ultimately becomes less alert which can impact attention span and the ability to absorb information.

When the body is exposed to extreme heat, it also reacts by sweating. Fluid is released to the skin which builds on the surface and evaporates into the air. However, depending on the humidity, the body’s mechanism of seating can be less effective as evaporation is decreased by the amount of moisture in the air — known as humidity. For this reason, Cheung said that it is not only temperature we need to be aware of when assessing the impact on the body and brain, but also the humidity.

“Twenty five degrees and dry and 25 degrees and very humid are very different,” he said. “And the combination of both temperature and the humidity and of adding energy to it is a much bigger challenge.”

While extreme temperatures can pose severe risks for individuals such as headaches, dehydration, heat exhaustion and, in severe cases, hyperthermia — especially for more vulnerable populations such as those with pre-existing health conditions — Cheung said even minor increases in temperature can impact cognitive function.

“You're being distracted because of that increased thermal discomfort,” he said. “Therefore you're not paying attention as much to your environment.”

Schools across Canada are facing the challenges posed by climate change.

One board in Quebec closed all schools on the first day, Tuesday, due to extreme heat. But school boards across Ontario are fighting the heat to keep schools open, sometimes without the necessary infrastructure to keep students and staff safe.


Minister of Education Stephen Lecce has been repeatedly criticized for cuts to public education.

(Government of Ontario)


Ontario is leading the way in Canada for investments in ventilation and air systems in schools, said Grace Lee, spokesperson for the Office of the Ministry of Education. She touted the success of implementing HEPA filters across school boards during and post pandemic, and an additional $1.4 billion “to ensure school facilities are renewed and repaired, including investing in air conditioners and other ventilation systems to improve air flow”.

These investments were not aimed at addressing high temperatures in classrooms, and even with them, the repair backlog is reaching $17 billion across the province.

“Students and staff in Ontario schools should never be forced to learn and work under conditions of extreme heat. This situation would be completely avoidable if the government invested in public education and school infrastructure,” Karen Littlewood, president of the Ontario Secondary School Teacher Federation (OSSTF), told The Pointer in an email statement. “The Ford government is directly responsible for so many students and staff needlessly suffering this week in extreme heat.”

A spokesperson for DPCDSB told The Pointer the opportunity to expand air conditioning in schools has been greatly hindered by a backlog in funding from the Ministry of Education. Approximately 60 percent of the board’s 151 schools are fully air conditioned with the remainder only served by partial air conditioned and select cooling centres — air conditioned portions of the school where classes can go for reprieve. And 50 of the 151 schools have portables for some classes, which have no temperature controls. While the exact date for when air conditioning is turned on or off predicated by the daily temperature, the spokesperson said units are only typically turned on between mid May and late September or early October. A spokesperson for the Peel District School Board (PDSB) told The Pointer 25 percent of its schools have portables and while not all schools have air conditioning, all have cooling stations. No response was provided about policy that governs when air conditioning is turned on or off. 

While the DPCDSB said it has made significant gains in investments to expand air conditioning, more support is needed from the province. While our weather patterns increasingly become more unpredictable, this means many more students may suffer, impacting not only their physical health, but their ability to learn.


Many schools in Peel have portables as a result of increasing student population. If they do not have air conditioning, other than opening the windows or having portable fans, students have few options to stay cool.

(Alexis Wright/The Pointer)

A campaign by the Ontario Ministry of Labour emphasizes that for every one degree increase in temperature, young workers are one percent more likely to be injured on the job. These injuries are not always caused by physical impairments due to excessive heat, but are often the result of being mentally distracted by physical discomfort. 

While the main overarching concern Cheung identifies is heat posing a distraction, school boards need to accommodate students and staff who may be more susceptible to the impacts of heat exposure. 

Young children are often more vulnerable to heat. A smaller body mass to surface area ratio can leave one more at risk of heat related morbidities. The heat also poses a greater risk for staff and students with preexisting health conditions. Due to the changes in blood flow, children and adults with heart conditions need to be more careful about heat stress. The same is true for those with asthma, which is one of the most common chronic conditions in children in Canada and is continuously increasing in prevalence. 

But it is not only physical conditions that can be exacerbated by heat. Studies show that exposure to heat can negatively impact those with mental health disorders. A 2022 report from the World Economic Forum cited several studies from the United Kingdom which found a link between exposure to extreme heat and worsening symptoms in people with depression, generalized anxiety disorder and bipolar disorder. 

Heat increases the release of cortisol — a stress hormone that is naturally occuring in everybody but higher in people with mental health conditions. Initially, high cortisol results in feelings of euphoria but can quickly change to irritability, emotional instability and depression. Heat also increases the release of adrenaline which puts the body into fight or flight mode which can increase anxiety and restlessness.

“In learning, certainly, they’re going to be more fidgety, they're going to be more just uncomfortable and distracted,” Cheung said. 

While cortisol and adrenaline levels can rise in any person in the extreme heat, people with diagnosed and medicated mental health illnesses are at an even greater risk. Lithium doses are often used to treat bipolar disorder, feeding a deficiency to stabilize mood swings. When the body is sweating profusely, it increases the toxicity of lithium which can be dangerous and even fatal. Mood stabilizers, antipsychotics and certain antidepressants make it more difficult for individuals to regulate body temperature putting them at greater risk for heat stress and hyperthermia. 

It is a problem that parents and educators need to increasingly become aware of. Between 2010 and 2013, dispensing rates of antipsychotics for those under 18 rose 33 percent, with antidepressants rising 63 percent in the same timeframe. The trend has only risen in the years since for both classes of medications. While usage rates of these medications are on the rise in youth due to the increasingly stressful circumstances they are living through, they are also widely used off label for a host of other conditions. A 2008 study in the Journal of Child and Adolescent Psychiatry and Mental Health found that 17 percent of antipsychotic prescriptions in youth were used in those living with attention deficit hyperactivity disorder — another diagnosis that is on the rise in the modern world.

As extreme heat becomes an increasing concern globally, so do the factors that put children at greater risk of heat related consequences, prompting researchers to suggest we need to rethink how we are keeping students and staff safe and healthy at school. 

Cheung cited a series of studies which showed how standardized test scores differ globally. There is a distinct correlation where countries that have hotter average temperatures, and often less access to things like air conditioning, fare poorer on tests than those residing in cooler climates. 

“It certainly can be the case that learning is going to be impaired, if children are going to be hot,” he said.


Teacher and educational workers unions have been on the picket lines fighting with the Ontario government for greater funding for public education which would allow updates to air quality systems.

(The Pointer files)


One tangible solution that OSSTF and other organizations are calling for is standards for air conditioning, but while Cheung said this is the obvious solution, he recognizes there are drawbacks which include increased energy usage and cost. Other potential solutions include having cooling centres, or shortening class periods to allow for more breaks, but he notes this can decrease learning time which may not suit educational goals. 

In hotter climates around the globe, school often begins earlier in the morning so pupils are released before the hottest time of the day, in order to optimize learning, while the potential negative consequences of extreme heat exposure are avoided. 

In Canada, our school system has been designed to break for the hottest months of the summer. But as our climate changes, the way students learn will have to adapt.



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Twitter: @rachelnadia_

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