Volunteers with Project Food Chain drop off water at the St. Felix 24-hr respite site in Toronto on June 19.Cole Burston/The Canadian Press
Stifling heat and damaging thunderstorms heralded the arrival of the summer solstice on Thursday, as parts of Eastern Canada stayed in the grips of a heat wave for a fourth consecutive day.
The longest day of the year in the Northern Hemisphere saw temperatures hover around 30 to 35 C across parts of Ontario, Quebec and Atlantic Canada, feeling more like 40 with the humidex.
The scorching temperatures were expected to last until Friday, except for parts of southern Ontario, where they are forecast to linger until Sunday.
Meteorologists have said this heat wave is rare so early in the season, and up there with the worst Eastern Canada has experienced in recent summers. Human-caused climate change, driven by the burning of fossil fuels, has upped the frequency and intensity of heat waves, scientists say.
Health officials have warned early season heat waves can be especially dangerous since many people are not acclimatized to summer temperatures.
In Montreal, the service that manages emergency medical calls said ambulance requests typically increase every day during a heat wave. Normally, Urgences-Sante receives 900 to 1,000 calls a day, said spokesperson Stephane Smith. This week, the corporation received 1,041 calls on Tuesday and 1,263 calls on Wednesday.
Smith said many of the people who call 911 have pre-existing medical conditions, including lung and heart problems, are elderly and living alone, or are unhoused. Many of them are experiencing heat stroke, weakness or dizziness, he said.
The increase in calls has put pressure on ambulance services, where there is already a labour shortage, Smith said.
At the Montreal General Hospital, emergency room physician Dr. Sanjeet Saluja said the heat wave is also putting a strain on hospital resources. People are coming in with fevers, difficulty breathing and signs of dehydration, he said, and are being rehydrated with IV fluids.
“You have patients who wouldn’t normally be here,” he said. “Normally at home they would be able to take care of themselves, but for different societal factors they can’t because of the heat and humidity.”
Saluja said the hospital has not seen any heat-related deaths this week. People should seek medical attention, he added, if they’ve been exposed to the heat and they have rapid breathing, vomiting, diarrhea, muscle cramping, severe headaches, or if their body temperature is above 40 C.
Authorities overseeing hospitals in Quebec City and Sherbrooke, Que., said they are not seeing unusual numbers at emergency rooms this week.
Montreal’s public health authority has not yet confirmed any deaths tied to the extreme temperatures, but said it’s investigating.
“The situation is evolving,” spokesperson Marianne Paquette said in an email statement. “If any deaths are indeed heat-related, we will confirm it in due course.”
At least 66 people died on the Island of Montreal as the result of an extreme heat wave in the summer of 2018. Of those who died, 72 per cent suffered from a chronic illness and 66 per cent were over the age of 65. In addition, 25 per cent of the heat wave victims had schizophrenia, and the health authority recommended Montreal do more to identify vulnerable people in need of attention during periods of extreme heat.
There have been no recorded heat-related deaths in Montreal since 2018, the agency said.
In Toronto, the city’s paramedic service said it had not seen a noticeable increase in heat-related calls over the last three days. It noted, however, that there are many symptoms associated with heat-related illness so calls may not be reported as heat-related at first.
Dr. Kyle Vojdani, chief and medical director at the emergency department at Michael Garron Hospital in Toronto, said capturing data on heat-related illness in the ER is challenging.
“Patients typically present with symptoms such as dizziness, headache, vomiting, and rash, rather than explicitly reporting heat-related issues. We can say anecdotally that patients are coming in to the ED with these symptoms which can later be attributed to heat-related illnesses once they are seen by a doctor,” Vojdani wrote in a statement.
“Based on our ED’s observations, and the increased temperatures we anticipate an increase in heat-related illnesses. We encourage anyone feeling unwell due to the heat to seek medical attention as appropriate.”
A pronounced and slow-moving high-pressure ridge has settled over eastern North America, trapping warm air and plunging the region into a stretch of hot and humid conditions. Eastern Canada is on the edge of that high-pressure system, where thunderstorms often form.
Toronto and other parts of southern Ontario were hit with rain showers and thunderstorms overnight into Thursday. Lanes on the city’s Gardiner Expressway were briefly blocked because of flooding, and thousands across Ontario were without power Thursday morning, according to local utilities, though progress was reported in some areas by early afternoon.
Montreal was placed under a severe thunderstorm watch on Thursday.
Atlantic Canada was also expecting similar high temperatures for most of New Brunswick, Nova Scotia and P.E.I., with central and eastern Newfoundland also under a heat warning.