As intense heatwaves continue to affect Pakistan and several other countries, millions of people are being exposed to dangerously high temperatures driven by climate change.
The growing frequency and intensity of heatwaves have raised concerns over how much heat the human body can safely tolerate during everyday activities.
Experts note that the answer is not straightforward, as humidity plays a critical role alongside temperature in determining how the body responds to heat.
A 2010 study suggested that a wet-bulb temperature of 35 degrees Celsius a measure combining heat and humidity represents the upper survival limit for humans in highly humid conditions.
Beyond this point, the human body struggles to cool itself through sweating, increasing the risk of heat exhaustion and heatstroke as body temperature rises.
However, with global temperatures continuing to climb in recent years, researchers have been re-examining the limits of human heat tolerance.
A 2023 study conducted by University of Roehampton found that the human body begins facing significant difficulty regulating heat at around 40 degrees Celsius, particularly in humid environments.
The study involved 13 adults who were exposed to varying levels of temperature and humidity while resting for one hour. Researchers conducted experiments in conditions ranging from 27C to 50C.
The findings showed that metabolic rate increases sharply when temperatures approach 40C, especially when humidity levels are high.
Researchers concluded that high humidity, combined with extreme heat, poses a greater threat to human health than temperature alone, as it limits the body’s ability to release heat effectively.
Experts suggests in such weather condition where temperature rise citizens should increase water intake to save them from dehydration.
Read also: PDMA forecasts severe heatwave alert in KP
