Sunstroke, dehydration, sunburn… The effects on our bodies of the scorching heat that France is experiencing are well known. But the risks to our mental health are less. However, they must be taken seriously, scientists warn, as heat waves will intensify due to climate change.
Perhaps the most visible symptom of our overheated brains is increased aggression. A phenomenon observed by many professionals in contact with the public, such as the police or caregivers.
increased aggression
“After 48 hours of intense heat, we observe an increase in aggressiveness that can go as far as physical violence,” Guillaume Fond, a psychiatrist at AP-HM (Public Assistance – Hospitals de Marseille) and researcher, confirms to BFTMV.com.
“Fortunately, this does not affect the entire population, but people who are predisposed to aggressiveness will act more easily in case of intense heat,” he specifies.
If the rate of “aggression” is difficult to quantify, science attests to an increase in violent crime when the mercury rises. Several studies demonstrate this, such as those carried out In finlandin the U.S, the Angels or even in South Africa.
A meta-analysis published in Science and synthesizing more than sixty studies on the subject he concludes from it a general increase in human conflicts of all kinds in case of intense heat but also during other significant climatic variations.
less focused students
Heat also has a more diffuse impact on our concentration, our memory and, more broadly, our cognitive abilities. The best way to see this is to observe student learning.
For a study published in 2020 in theAmerican Economic Journal, researchers have analyzed the results of several million students on the PSAT, a test that precedes the college entrance exam in the United States. “Without air conditioning, a 1°F (about 0.5°C) warmer school year reduces learning by 1%,” they concluded.
The little ones are no exception. Last July, a UNICEF report warned: “Heat waves are affecting children’s ability to concentrate and learn, putting their education at risk.”
cortisol secretion
How to explain this effect of heat on our mind? The first reason is chemical. “Like our entire body, the brain, made up of more than 80% water, also suffers from heat,” explains Jérôme Palazzolo, a psychiatrist and researcher at the University of Nice-Côte d’Azur, to BFMTV.com.
“Faced with a decrease in cerebral irrigation, the organism activates an adaptation mechanism that translates into a greater secretion of cortisol and dopamine, hormones that will put us in a state of hypervigilance. This generates stress or even anxiety” in some people, explains the researcher.
The second reason is indirect but is at the root of many heat related ailments. It’s about sleep. “The heat prevents us from sleeping well. It wakes us up and alters our sleep cycles (light, deep, paradoxical…)”, continues psychiatrist Jérôme Palazzolo. We have known for a long time that sleep affects our morale.
“It’s not so much the heat that counts but the night temperature, says the AP-HM doctor Guillaume Fond. If it’s too high, it impairs our ability to recover.”
eco-anxiety
More recently, another phenomenon has been added to these physical reactions to heat: eco-anxiety. Appearing around the year 2020, the term is defined by the suffering and anguish in the face of climate change and the destruction of biodiversity by human beings.
“Eco-anxiety is born with a violent consideration of the climatic situation associated with a very strong feeling of helplessness”, describes the psychiatrist of the AP-HM Guillaume Fond, who specifies that it is not “in any case a psychiatric disorder”. “. “It is even a rather healthy reaction,” underlines this member of a research committee on health and climate within the AP-HM.
For people with ecological anxiety, the heat is no longer synonymous with vacations and relaxation. As heat waves multiply and the heat wave breaks new records every year, they find it hard not to think about global warming.
“It is not a reason for consultation, but it is something that many young patients talk about,” says Guillaume Fond.
All these elements, together, draw a summer period that is not easy for everyone to go through. Some psychiatrists, like the American Cynthia Rosenthal, go so far as to speak of seasonal depression, which therefore would not be exclusive to winter.
Source: BFM TV
