This summer’s record temperatures are revealing the toll climate change is taking on mental health. In France, psychiatric emergency services have reported a spike in calls during heatwaves, while experts warn the heat can worsen existing mental health issues. Meanwhile, young people are feeling overwhelmed by climate anxiety, as temperatures push past 40C.
At Sainte-Anne hospital in Paris, psychiatric emergency services report seeing more patients during heatwaves. For French psychiatrists, this is a warning sign of what lies ahead as summers get hotter.
“You may think you’re not affected because you’re young. But it will affect the healthy population as much as other groups,” Suzana Andrei, secretary-general of the French Federation of Psychiatry, told RFI.
People already living with a mental health condition are at the greatest risk.
“Even if it is mild, it will be made worse by a heatwave that consumes a person’s physical and mental coping resources,” Andrei added.
A study in the International Journal of Environmental Research and Public Health, published in July, found that people with bipolar disorder are more likely to see their condition suddenly worsen during heat spikes.
Medication too can be affected by hot weather, Andrei warns. “Dehydration is never far away. So the medicine becomes more concentrated in the blood and side effects can be felt in a much more unpleasant way than usual."
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Climate anxiety
When temperatures climb, physical reactions can include sweating, headaches and faster breathing – symptoms that can trigger anxiety even in people with no prior history of it.
The body also reacts by producing cortisol – the stress hormone – to help cope with danger.
"Cortisol normally helps us adapt to temperature changes. But when the heat is very intense and lasts for several days, cortisol production can’t keep up, and the body’s stress system gets overwhelmed," Andrei said.
This summer has seen periods of extreme heat across Europe, with June and July ranked among the hottest ever recorded – which are feeding eco-anxiety.
“It can affect people with no previous mental health issues – sometimes those very active in public life and committed to their community’s future. This fear can trigger a wider anxiety disorder,” Andrei explained.
Young people are particularly vulnerable to anxiety over climate change. In a 2023 European study, 45 percent of people aged 16 to 25 said that eco-anxiety had a significant impact on their daily lives.
The impact of heat affects some more than others, given that access to insulated housing, a cool workplace or a psychologist is determined by a person's income and status. People in precarious situations often lack these protections, putting them more at risk of heat stress.
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Increase in domestic violence
Researchers also warn of the effect of extreme heat on social issues, including domestic violence.
A report from the United Nations Spotlight Initiative – a global project aimed at ending violence against women and girls – links each 1C of warming to a 4.7 percent rise in intimate partner violence.
At 2C, that would mean 40 million more women and girls facing such abuse every year by 2090.
A separate study, published in the International Journal of Environmental Research and Public Health in June, found consistent connections between higher temperatures and violence against women worldwide.
Scientists say heat-induced stress can reduce self-control and increase irritation – one reason extreme heat is linked with higher incidences of aggression and violence.
And direct exposure to extreme climate events can magnify this effect, as France’s psychiatry federation observed during the wildfires around Marseille in early summer 2025.
“It causes acute stress for people living in the area. Vulnerability, psychological distress that can be long term, even post-traumatic stress,” said Andrei.
With Europe warming faster than any other continent, psychiatrists expect more heat-linked stress in summers ahead – from spikes in emergency visits to longer-term anxiety and trauma.
Partially adapted from this article by RFI's French service
