Toronto-World Health Organization says climate change heat is a “public health crisis” for workers around the world and experts say Canada is no exception.
The WHO and World Meeptorological Organization (WMO) on Friday released a joint report stating that external activists are at high risk of construction, farming and other physically demanded jobs, especially heat stroke, dehydration, heart damage and renal dysfunction.
Although radiation from the sun is an additional risk factor at the top of the air temperature, the report states that people working indoors in hot, humid conditions are also weak, especially if the heat is getting away from the machinery, such as in manufacturing plants.
“Activists running our societies are paying the highest price,” said Ridiger Creche, “The WHO’s Environment Director, Climate Change and Health said in a news briefing in Geneva on Thursday.”
“These effects are particularly serious in weak communities with limited access to cooling, health care and productive labor policies.”
Ottawa Research President Glenn Kenny contributed to the international report and said that people may think that Canadian workers are not weak as workers in the world’s hotter parts, but this is a mistake.
“Unfortunately in Canada, we have these seasons extremes. We go from cold to hot. And so our bodies essentially lose that (heat) adaptation during the winter period,” he said in an interview.
The report states that the risk of heat tiredness increases when the body temperature rises more than 38 C.
This urged governments and employers to develop heat-health schemes, including taking brakes for workers and getting out of the sun or moving away from hot machinery and regular rebellion.
Employers can also plan shifts and workloads so that the most physically demanded work during day or evening coolers. The report states that they can also reduce the intensity of the work in the high heat period, either by reducing the speed of the work or by incorporating more brakes, the report states.
Whenever possible, workers should wear clothes that allow the heat to avoid, while still meets safety requirements for protective gear.
Kenny said that for every individual worker it is important for heat copping strategies for tailor heat, which are older, chronic health conditions or physically less fit.
He said that the ability to dissolve heat from the body decreases as the age of the people, he said.
Kenny said that there is also a need to consider the cumulative impact of working during the summer day after the day.
He said that it is important to stay cool and rest out of work hours, but those off-hour would not be allowed to recover completely during the intense heat during the five-day work week, he said.
Kenny said, “The body is essentially compromised because we go through the week of work.”
“If I take a worker on Monday and see their body’s ability to lose heat, they are not the same person for five days,” he said.
“They have low heat ability and should be responsible for it.”
The report states that the body gets rid of heat by increasing blood flow to the skin and through sweat.
When the air is hot compared to the skin, the body is heat and more sweating may occur to regulate the body temperature because excessive sweating is required.
Kenny said that in turn pressures the heart and kidney because “we have only a certain amount of blood,” Kenny said.
“As you steal (water) away from that amount of blood because you are sweating … you are finishing the body,” he said.
Dr. Melissa Lam, a family doctor at Vancouver and the President of the Canadian Association of Physician for the environment, said that heat stress affects activists safety in many ways.
Lem said, “Workers’ cognitive tasks can be impaired, so they may have more troubles, suffer from their performance, they have a high rate of injury,” Lem said.
“And then when you are breathing fast because you are overheating, you are also breathing in more air pollution that can reduce the loss of heat health.”
The WHO/WMO report recommends that workers should be added to the “big system” so that they can look out for signs of heat stress.
Signs of heat tiredness include fatigue, weakness, dizziness, lighting, thirst and light muscle cramps. If they are, the worker should be taken to a quiet area and drink water or electrolyte drinks.
If the symptoms do not improve after 15 minutes, heat tiredness may be severe. Additional signs of severe heat exhaustion include slow response time, severe muscle cramps, blurred vision, headache or nausea.
The most severe form of heat stress is the heat stroke, a medical emergency and it requires “aggressive cooling” with ice and cold water and an ambulance should be called, the report states. Symptoms of heat stroke may include vomiting, irregular behavior, confusion or disorientation, guard speech, hysteria, delirium, shivering, convulsions and loss of consciousness.
Lem said that after reading the report, he was “taken back to 2021 heat dome (in BC), when I ever saw patients with heat disease throughout my career.”
Most of the more than 600 people who died in that summer were the elderly and their non-air were isolated inside air-conditioned houses, but they believe that many additional people who had become ill were potential laborers.
He said that for climate change heat for safety of workers, it is also important to address the root causes, he said.
“One of the best ways to protect them is to caping greenhouse gas emissions and reduce our use and extraction of fossil fuels,” Lem said.
He said, “This will have more impact by reducing air pollution, which exposes the workers,” he said.
This report of Canadian Press was first published on 22 August 2025.
Canadian press health coverage receive support through partnership with Canadian Medical Association. CP is completely responsible for this material.
Nicole Ireland, Canadian Press