Science pinpoints the exact temperature at which the body begins to seriously compromise

Research led by Professor Lewis Halsey of Roehampton University and his team found that humans have an upper critical temperature. The team is currently conducting additional research to explain the increased metabolic energy costs at high temperatures.

Scientists have found that resting metabolic rate (a measure of the energy the body uses to keep going and perform vital functions) is higher when people are exposed to heat and humidity. “A lot of work has been done on temperature ranges to achieve the lowest metabolic rate and thus lower energy expenditure. However, much less information is available. For humans, when considering the upper limit of the thermoneutral zone

Halsey said.

Knowing the temperature at which human metabolic rates start to rise and how they vary between people can provide “fundamental insights into how we respond to suboptimal environments and how ‘optimum’ differs between people with different characteristics,” they explain. “.

An increase in outside temperature gradually activates the body’s mechanisms Combat heat, such as sweating, vasodilation, thirst, or the sensation of hyperventilation when the temperature rises.

Temperature is too high

It is concluded that the upper critical temperature Humans are at a temperature of 40°C, from which the cost of metabolizing energy increases exponentially and the compensatory mechanisms available to the organism begin to cease to be effective.

The study involved 13 people, aged 23 to 58, seven of whom were women. They all rested in a room where the temperature was gradually raised from 28 degrees for an hour and the humidity was controlled.

Each participant was exposed to five temperature conditions for one hour while resting in an elevated temperature, humidity-controlled room to observe the effects and changes in the body.

“We found considerable variation in the response of heart function to heat between different categories of people, the most novel of which was between the sexes,” Halsey said. “That is, on average, male and female cardiac Blood vessels exhibit some key differences in how they respond to heat,” he added, detailing that Women’s bodies respond worse to heat.