Rising heat a ‘public health crisis’ for workers, including in Canada: WHO
Climate Change-Driven Heat a Growing Health Crisis for Canadian Workers
TORONTO — The World Health Organization has declared climate change-driven heat as a “public health crisis” for workers globally, and experts warn that Canada is no exception.
A joint report by the WHO and the World Meteorological Organization (WMO) highlights the increased risk of heat stroke, dehydration, cardiovascular damage, and kidney dysfunction faced by outdoor workers in physically demanding jobs such as construction and farming. However, indoor workers in hot, humid conditions, particularly those exposed to heat radiating from machinery in manufacturing plants, are also vulnerable.
Rüdiger Krech, the WHO’s director of environment, climate change, and health, emphasized that “the workers keeping our societies running are paying the highest price,” especially in communities with limited access to cooling, healthcare, and labour policies.
Heat Adaptation Challenges in Canada
Glen Kenny, University of Ottawa research chair in environmental physiology, noted that Canadian workers face unique challenges due to weather extremes, transitioning from cold to hot temperatures. As the body loses its heat adaptation during the winter, workers become more vulnerable to heat-related illnesses.
The report underlines that the risk of heat exhaustion escalates when the core body temperature exceeds 38°C, urging governments and employers to develop heat-health plans. These plans should include strategies for workers to take breaks, seek shade, stay hydrated, and adjust workloads to cooler times of the day.
Personalized Heat Coping Strategies
Kenny stressed the importance of tailoring heat coping strategies to individual workers, considering factors like age, chronic health conditions, and physical fitness. As the body’s ability to dissipate heat diminishes with age, and prolonged exposure to heat can compromise heat loss capacity over time.
Dr. Melissa Lem, a family physician in Vancouver, highlighted the cognitive and physical impairments caused by heat stress, leading to reduced performance, higher injury rates, and increased exposure to air pollution.
Recognizing Heat-Related Illnesses
The report recommends implementing a “buddy system” for workers to monitor signs of heat stress, such as fatigue, dizziness, and muscle cramps. Severe symptoms like slow reaction time, blurred vision, or confusion indicate a need for immediate cooling measures and medical attention to prevent heat stroke.
Addressing the root causes of climate change-driven heat is crucial to protecting workers, with a focus on reducing greenhouse gas emissions and air pollution. By taking proactive measures, Canada can safeguard its workforce from the escalating health risks posed by rising temperatures.
This article by The Canadian Press was originally published on August 22, 2025. Canadian Press health coverage is supported by the Canadian Medical Association.
Nicole Ireland, The Canadian Press
