A recent study of Pennsylvania State Universityrevealed that human beings have less tolerance for high temperatures than previously believed and lowered several degrees Celsius, the maximum to which they could be exposed.
To make the measurement, the researchers relied on the so-called “wet bulb,” which basically translates to and represents a temperature humid in which the air is saturated and retains as much moisture as it can in the form of water vapour; a person’s sweat will not evaporate at that skin temperature.
In previous studies it was said that the human being resisted up to 35 degrees Celsius (equal to 95 ° F at 100% humidity or 115 ° F at 50% humidity), however, the new indicated maximum is only 31 degrees Celsius ( equal to 87ºF).
W. Larry Kenney, professor of physiology and kinesiology and the Marie Underhill Noll Chair in Human Performance, said the results could help people better plan for extreme heat events made more frequent by climate change.
“If we know what those upper limits of temperature and humidity are, we can better prepare people, especially those who are most vulnerable, before a heat wave. That could mean prioritizing the sickest people who need care, setting alerts to go out into a community when a heat wave is approaching, or developing a chart that provides guidance for different temperature and humidity ranges.”
Of course, there is an important point of the investigation and that is that this maximum temperature supported by the human body occurs only in humid climates, since in dry places sweat can evaporate on the skin.
For this study, recently published in the Journal of Applied Physiology, The researchers recruited 24 participants between the ages of 18 and 34 years. While the researchers plan to conduct these experiments in older adults as well, they wanted to start with younger people.
“Young, fit, healthy people tend to tolerate heat better, so they will have a temperature cutoff that can work as a ‘best-case’ baseline,” Kenney said. “Elderly people, people on medication and other vulnerable populations will probably have a tolerance limit below that.”