Humans have been found to have a lower tolerance for extreme heat than previously thought. This is likely to become a major issue as temperatures rise.
A University of Ottawa study said the findings highlighted the urgent need to fully address the impact of climate change on human health.
“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,” Senior Postdoctoral Fellow Glen Kenny said.
“This is critical information as we face increasing global temperatures.”
The study report said that many regions might soon experience heat and humidity levels that exceeded the safe limits for human survival.
The researchers exposed 12 volunteers to various heat and humidity conditions to identify the point at which thermoregulation (the body adjusting to the heat) becomes impossible.
Participants were subjected to extreme conditions, 42°C with 57 percent humidity, representing a humidex of approximately 62°C.
During the tests, the participants’ core temperature “streamed upwards unabated” and many could not complete the nine-hour exposure.
“The implications of this research extend beyond academia,” the study report said.
“As cities prepare for hotter summers, understanding these limits can help guide health policies and public safety measures.”
The study titled “Validating new limits for human thermoregulation” was published in the Journal PNAS.
