A study from the University of Ottawa鈥檚 has confirmed that the limits for human thermoregulation鈥攐ur ability to maintain a stable body temperature in extreme heat鈥攁re lower than previously thought.
This research, led by Dr. , former Senior Postdoctoral Fellow and Dr. Glen Kenny, Director of and professor of physiology at 91精品黑料吃瓜's Faculty of Health Sciences, highlights the urgent need to address the impacts of climate change on human health.
The study found that many regions may soon experience heat and humidity levels that exceed the safe limits for human survival. "Our research provided important data supporting recent suggestions that the conditions under which humans can effectively regulate their body temperature are actually much lower than earlier models suggested," states Kenny. "This is critical information as we face increasing global temperatures."
鈥淭he conditions under which humans can effectively regulate their body temperature are actually much lower than earlier models suggested鈥
Glen Kenny
鈥 Director of HEPRU and professor of physiology at 91精品黑料吃瓜's Faculty of Health Sciences
Utilizing a widely used technique known as thermal-step protocols, Meade and his team exposed 12 volunteers to various heat and humidity conditions to identify the point at which thermoregulation becomes impossible. What made this study different, was that participants returned to the laboratory for a daylong exposure to conditions just above their estimated limit for thermoregulation. Participants were subjected to extreme conditions, 42掳C with 57% humidity, representing a humidex of approximately 62掳C. 鈥淭he results were clear. The participants鈥 core temperature streamed upwards unabated, and many participants were unable to finish the 9-hour exposure. These data provide the first direct validation of thermal step protocols, which have been used to estimate upper limits for thermoregulation for nearly 50 years鈥, says Meade.
"Our findings especially timely, given estimated limits for thermoregulation are being 鈥 explains Meade. "They also underscore the physiological strain experienced during prolonged exposure to extreme heat, which is becoming more common due to climate change."
The implications of this research extend beyond academia. As cities prepare for hotter summers, understanding these limits can help guide health policies and public safety measures. "By integrating physiological data with climate models, we hope to better predict and prepare for heat-related health issues," adds Kenny.
As the world grapples with the realities of climate change, this research aims to spark important conversations about our safety and adaptability in increasingly extreme environments.
For more information, read the study titled 鈥鈥,&苍产蝉辫;published in the Journal PNAS.