While it is commonly known that extreme heat can be dangerous for people's physical health — from heatstrokes to an increased risk of blood clots — the effect of it on our mental health is less commonly known, even though these risks are equally concerning.
So far, this year is historically hot across most continents, from heatwaves resulting in a surge in forest fires in Europe to glaciers melting at record speeds. Experts have now warned that this is just the start, and that future summers could see continents sweltering in even higher temperatures.
Aside from this having disastrous consequences for vulnerable plant species, as well as seas, oceans and marine life, an increasing number of days with above-average temperatures could result in an annual spike in visits to emergency rooms for mental health crises, global crime rates and suicide rates.
Belgium, too, has been engulfed in heat in the past weeks and is now facing its warmest week this year. Have you experienced increased anxiety, stress, or another form of deteriorating mental health? Find out why this is.
Chemical reactions
Where the shorter autumn and winter days can see people develop Seasonal Affective Disorder (SAD), a type of depression that is most commonly thought to be linked to the lack of sunlight which stops the hypothalamus from working properly and can result in chemical reactions that make people feel sleepy and lethargic, hot temperatures can increase the stress hormone cortisol.
Excessive levels of this hormone can give people a sense of euphoria, however, prolonged exposure of the brain to a high concentration of cortisol can result in negative side effects, such as irritability, emotional lability, and depression.
Additionally, extremely warm temperatures can deregulate serotonin levels, neurotransmitters that are important for the feeling of happiness, which can make people more vulnerable to depression.
While sunny weather is usually linked to increased happiness, it can increase feelings of anxiety and depression. Credit: Belga/ NICOLAS MAETERLINCK
Research cited by the World Economic Forum (WEF) showed that, for every 1°C increase in monthly average temperature, mental health-related deaths increase by 2.2%.
On extremely hot summer days, adults in the United States were at an increased risk of visiting emergency rooms for mental health crises related to substance use, anxiety and stress, among others, one study by the Boston University's School of Public Health found.
A recent Belgian study even found that in places with temperate climates, high temperatures can trigger suicide deaths up to one week later. One of the study’s researchers, professor of environmental epidemiology Tim Nawrot, told VRT News that the heat is not necessarily the primary cause, but can be a “trigger” to make the final decision.
In addition to chemical reactions increasing the risk of these mental health issues, the sense that people have to make the most of warm weather with social commitments can also add to the sense of anxiety.
Making matters worse, the effectiveness of important medicines that are used to treat psychiatric and mental health illnesses can be reduced by the effects of heat, or work differently.
Soaring crime rates
Aside from impacting people’s mental health, heatwaves also affect cognitive ability and can result in increasing aggressive behaviour and skyrocketing crime rates, according to the World Economic Form
One study found that students in rooms without air-conditioning during a heatwave performed 13% worse than their peers in cooler rooms in cognitive tests, and also had 13% slower reaction time.
People struggling to think clearly are more likely to become frustrated. Serotonin, the previously mentioned chemical that impacts people’s vulnerability to depression, also keeps levels of aggression in check. When heat impacts the production of the chemical, this can also lead to increased aggression.
Staying hydrated can help avoid overheating your body, which in turn can help decrease the risk of negative mental health effects. Credit: Belga / Nicolas Maeterlinck
This becomes evident when looking at the number of violent crimes that are committed, which increases when the mercury rises. “Even just a 1-2°C increase in ambient temperatures can lead to a 3-5% spike in assaults,” a World Economic Forum report read.
With climate change increasing the number of very warm days, it is estimated this could result in a 5% increase in all crime categories globally by 2090.
Reminder that changes are needed
The World Economic Forum stressed that heatwaves and the impact on our mental health are “important reminders that the best thing we can do to help ourselves and future generations is to act on climate change.”
Researchers from the Belgian study stressed that its results highlight that adaptation strategies must take into consideration the effects of temperature on mental health, while the Boston University study stressed that clinicians should expect to see an increase in patients requiring mental health services during periods of extreme warmth.
Related News
- 'Like a boiling egg': How the heatwave affects your body
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- Five tips to cool your home after days of extreme hot weather
“On days of extreme heat, it is important that we each take the precautions necessary to take care of ourselves and our loved ones,” the study's lead author Amruta Nori-Sarma, said.
Those in need of a listening ear or with any questions about suicide can contact the Suicide Line anonymously on the toll-free number 1813 or at www.zelfmoord1813.be in Dutch, at 0800 32 123 in French, or at 02 648 40 14 in English.
