"Breaking Record-Breaking Heat"... What Is the Maximum Temperature Humans Can Endure?

Metabolic Rate Surges Beyond Certain Temperature
"More Energy Consumed When Hot and Humid"

This summer, as record-breaking high temperatures are being recorded across the globe, a study on the 'maximum temperature limit' that humans can endure has been released, drawing significant attention.

On the 6th (local time), Professor Lewis Halsey and his research team at the University of Roehampton in the UK published the results of an experiment measuring the human 'critical high temperature' in the international academic journal 'The Journal of Experimental Biology.' The critical high temperature measures the maximum temperature limit that humans can withstand.

The research team recruited 37 participants and observed how their metabolic rates changed according to temperature and humidity. Metabolic rate refers to the amount of energy consumed by animals, including humans, while resting without any special activity.

First, the team measured resting metabolic rate, skin temperature, core temperature, and heart rate in a room temperature environment. Then, they compared these measurements with those taken at 50 degrees Celsius and 25% humidity.

On the afternoon of the 3rd, which showed hot weather, elderly people are resting in the shade of Seoul Station Plaza.
[Image source=Yonhap News]

The experiment showed that in hot and humid environments, human metabolic rate increased by up to 56% compared to resting conditions. Accordingly, the measured human critical high temperature was between 40 and 50 degrees Celsius.

Professor Halsey, who led the study, explained the reason for conducting the research, saying, "There has already been extensive research on the temperatures at which animals can survive using minimal energy," but "there had been no such research on humans."

He added, "Through critical high temperature research, we can understand how humans respond to 'extreme environments that are not optimal,' and also how the 'optimal environment' differs from person to person."

The reason why human metabolic rate increases at the critical high temperature of 40 to 50 degrees Celsius is still under investigation. However, Professor Halsey revealed that "when people are exposed to hot and humid environments, the amount of energy required for physical activity is higher."

Meanwhile, according to the U.S. National Centers for Environmental Prediction, as of the 4th, the global average temperature recorded 17.18 degrees Celsius, setting a new record high. Consequently, heatwaves around 40 degrees Celsius are being observed worldwide.

In early last month, many parts of Southeast Asia, including Vietnam and Thailand, experienced daytime high temperatures well above 40 degrees Celsius. On the 21st of last month, the daytime temperature in Austin, Texas, USA, reached 40 degrees Celsius, with a heat index reflecting humidity soaring up to 48 degrees Celsius.

This content was produced with the assistance of AI translation services.