How hot is considered "too hot"?, For humans, body | increase | possibility | humidity | metabolic rate | experiment | temperature | research
On July 4th, Earth recorded the hottest day ever. So, what is the temperature limit that humans can safely tolerate? On the 6th, the research team of Arhat Puton University reported that there is an upper limit critical temperature for human beings, which may be between 40 ℃ and 50 ℃. Understanding the temperature values that lead to an increase in metabolic rate and how individual temperatures change may have important guiding significance for work, exercise, tourism, and more. This study is a continuation of their previous research published in the journal Physiology Reports.
Research has found that when people are exposed to environments between 40 ℃ and 50 ℃, their resting metabolic rate may be higher. Resting metabolic rate is an indicator that measures how much energy the human body consumes to maintain normal bodily function. In short, it is the minimum amount of energy consumed in a stationary state.
Previous experiments conducted by the research team have shown that when people are exposed to temperatures of at least 40 ℃, their resting metabolic rate increases. At 40 ℃ and 25% humidity, the metabolic rate of participants increased by an average of 35% compared to baseline. At 50 ℃ and 50% humidity, people's core temperature increased by an average of 1 ℃, metabolic rate increased by 48% compared to baseline, and heart rate increased by 64%.
Researchers suggest that this means that the hotter the environment, the harder the body must work to maintain normal functioning.
In the latest experiment released on the 6th, researchers used echocardiography or echocardiography to examine the cardiac activity of 24 participants at 50 ℃ and 25% humidity. It was found that women's heart rate increased more on average than men's. This may indicate that the female body is not efficient in dissipating excess heat.