Is the heatwave slowing down your brain?

Research finds that cognitive functions decline as temperatures rise

(Image credit: Spencer Platt/Getty Images)

Hot weather really does fry our brains, a new study has confirmed.

Researchers at Harvard University found that people who were exposed to hotter temperatures “did significantly less well” in cognitive and memory retention tests than people in air-conditioned environments.

The research, published in the journal Plos Medicine, focused on 44 students at a Boston university. Half of the subjects had been assigned to dorm accommodation with air conditioning, while the other half lived in halls without it.

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“They were followed before, during and after a five-day heatwave, when the indoor temperatures exceeded 26C without air conditioning,” The Times reports.

“The students performed two cognition tests, measuring processing speed and working memory - and when the temperature rose, the scores of those in the hotter accommodation dropped by about 13% compared with their air-conditioned peers,” the newspaper continues.

Memo Cedeno, from Harvard Chan School of Public Health, said the research shows that “even strong and healthy people” suffer impaired intelligence in the heat. “We see news pieces on heatwaves and mortality in older people, but the rest of us feel immune,” he noted.

The reality, that all types of people are affected mentally, “could be because of loss of bodily fluids”, Cedeno added, or because the brain is working harder maintaining critical functions such as thermoregulation.

The researchers have “recommended the roll-out of sustainable air conditioning systems wherever possible”, reports The Independent.

However, Professor Max Headley, a physiologist at the University of Bristol, suggests that the study has made “a mountain out of a molehill”. Scientists were already aware of the mental impact of tiredness and thirst, which are the likely factors at play in the Harvard research, he argues.

“To my mind, the observations can be readily explained by simple physiological factors that are entirely predictable. I can’t see that it’s anything to get excited about,” Headley said.

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