A team of scientists from the University of Roehampton (UK) has determined that the upper limit of critical temperature for human survival is in the range of 40°C to 50°C, reports Neuroscience News.
As part of the study, the researchers measured the metabolic rate — the amount of energy consumed by the body during a specific period of time — of a group of 13 volunteers, who were subjected to different temperatures and humidity while they were at rest. The results showed that heat and humidity increase this index.
At temperatures above 40°C, metabolism accelerated by an average of 35%. According to scientists, this indicates that the body's adaptive abilities have reached their limit.
"Various investigations have been done on the optimal temperature range for the life of different animal species in terms of their metabolic rates being minimal and therefore their energy expenditure being low. Interestingly, much less is known about the limits above the human neutral thermal zone," said Professor Lewis Halsey, lead author of the study.
Understanding the temperatures at which people's metabolic rates begin to rise and how they vary could have implications for working conditions, sport, medicine and travel. "This research provides fundamental insights into how we react to 'sub-optimal' environments and how 'optimal' ones differ in people with different characteristics," Halsey added.
The scientists also looked at the effects of extreme temperatures on heart function in people of different ages and physical condition. An echocardiograph was used for this trial. Their results showed that both men and women have "some key differences in the way their cardiovascular systems respond to heat." (RT) (Photo: University of Roehampton)