The heat wave is taking root in the country, while peaks of 40°C are expected, with the south reaching 45°C. Temperatures that are theoretically bearable, but can prove dangerous for the body even without precautions.
A mercury that rises to 35 °C or 40 °C or locally even 45 °C. With the heat wave expected in France over the next few days, human bodies will be put to the test. But what temperatures can we withstand? If age and health are a factor, the duration of exposure to heat also plays a crucial role.
While the ideal human body temperature is between 36°C and 37.8°C, the thermometer is expected to exceed this limit in the coming days. Other regions of the world are even experiencing episodes of extreme heat, with India recently hitting 50ºC.
Despite the obvious discomfort, these temperatures remain tolerable for humans, who can withstand up to 100°C during a sauna session. However, this type of experience must remain brief, generally 10 to 15 minutes, and is not recommended for a person with a fragile heart.
“The human body can withstand high temperatures as long as it doesn’t happen over a long period of time,” explains Dr. Jean-Louis Bensoussan, doctor and general secretary of the association of general practitioners MG France, told BFMTV.com.
“The advantage we have is that the nights are pretty cool at the moment, between 21°C and 24°C. This is an important element that gives the body time to cool down. It would be different, it was over 30C at night,” he said.
“Heat stroke from 30°C”
In intense heat, it’s important to protect yourself from dehydration or discomfort without necessarily keeping an eye on the thermometer.
“From 30°C we can get heat stroke without protection, we all see that in summer, for example on the beaches,” warns the doctor.
In addition to the question of temperature, humidity also has an impact on the weather conditions that the human body can withstand. An element measured with a tool: the wet bulb. This measurement, whose unit is TW, includes both heat and moisture in the air.
According to a study by the American Physiological Society published last January, the maximum tolerable rate for humans is 35 TW.
“Moist air makes the situation worse, it poses risks of respiratory complications,” says the general secretary of MG France.
“Age is a complicating factor”
It is clear that we are not all the same in the face of the heat and that part of the population needs special attention.
“Age is a complicating factor (given the risks posed by heat),” emphasizes Dr. Jean-Louis Bensoussan, who recalls that “both infants and the elderly” constitute a vulnerable public in times of heat waves.
For the coming days, the doctor advises the entire population to be cautious. The reflex must be to hydrate regularly.
“You have to drink and cool your body by getting wet and letting the water evaporate. It replaces sweat when you sweat a lot and don’t have enough,” he recommends.
During a prolonged heatwave, Jean-Louis Bensoussan recommends being “very vigilant”, especially around the elderly. “You have to ask for them because they have trouble following the recommendations,” he says. After a peak expected on Friday or Saturday, depending on the region, the thermometer is expected to gradually drop from Sunday.