The heat wave is settling in the country, while peaks of 40°C are expected, or even 45°C locally in the South. Temperatures that are theoretically bearable, but which can already prove to be dangerous for the body without taking precautions.
A mercury that rises to 35°C or 40°C, or even 45°C locally. With the heat wave expected in France for the next few days, human bodies will be put to the test. But what temperatures are we able to withstand? If age and state of health matter, the duration of exposure to heat is also a key element.
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 50°C recently reached in India.
Despite the obvious discomfort, these temperatures remain bearable for humans who can withstand up to 100°C during a sauna session. However, this type of experience must remain short, 10 to 15 minutes in general, and is not recommended for a person with a fragile heart.
“The human body can withstand high temperatures as long as it is not for a prolonged period”, explains to BFMTV.com Dr. Jean-Louis Bensoussan, doctor and general secretary of the union of general practitioners MG France.
“The advantage we have is that the nights are quite cool at the moment, between 21°C and 24°C. This is an important element which gives the body time to cool off. It would be something else s It was over 30°C at night,” he said.
“Heat strokes from 30°C”
In case of strong heat, the important thing is to protect yourself against the risk of dehydration or discomfort without necessarily keeping your eyes riveted on the thermometer.
“We can get a heat stroke from 30°C without protection, we all see it in the summer on the beaches for example”, warns the doctor.
More than just the question of temperature, the amount of humidity in the air also has consequences on the weather conditions that the human body can withstand. An element measured using a tool: the wet bulb. This measurement, whose unit is TW, includes both heat and humidity in the air.
The maximum bearable rate for humans is 35 TW, according to a study by the American Physiological Society, published last January.
“Damp air makes things worse, it brings risks of respiratory complications”, abounds the secretary general of MG France.
“Age is an aggravating factor”
It is clear that in the face of heat, we are not all equal and that part of the population requires special attention.
“Age is an aggravating factor (in the face of the risks induced by heat)”, underlines Dr Jean-Louis Bensoussan, who recalls that “both infants and the elderly” constitute a public at risk in times of heat wave.
For the days to come, the doctor recommends caution for the entire population. 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 you don’t have enough,” he recommends.
In the event of a prolonged heat wave, Jean-Louis Bensoussan recommends being “very vigilant”, especially in the case of the elderly. “You have to ask about them because they have trouble following the recommendations,” he says. After a peak expected on Friday or Saturday, depending on the region, the thermometer should gradually drop from Sunday.