Too hot, too cold, just right: How studies say climate affects brain function

In 2023, the U.S. had record-breaking snow levels during the winter season, followed by a nationwide summer heat wave that’s currently melting the country, according to Deseret News.

And amid the meteorology mayhem, several news sources reported that it’s not only our heat and air conditioner bills we have to keep up with: Cognitive function is also at risk.

Multiple online news platforms said that extreme heat and extreme cold can negatively affect how your brain works

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How does extreme heat affect your brain?

NPR reported that increased heat can slow the body’s reaction time, make people moodier or more irritated and lower activity in the parasympathetic nervous system, where the main function is to relax the body.

“Plus oxygen saturation levels in the blood were lower at the elevated temperatures as well, which the researchers said could be expected to result in reduced cognitive performance,” NPR said.

Caleb Dresser, an emergency medicine physician who directs health care solutions at the Harvard Chan Center for Climate, Health and Global Environment, told NPR that “evidence suggests that heat can influence us in sometimes-indiscernible ways.”

“All of these [studies] seem to point to a reduced ability to think clearly and quickly and efficiently when the body is too hot,” Dresser told NPR.

Time said high temperatures have been associated with higher suicide rates, crime and violence.

Shabab Wahid, a mental health expert at Georgetown University’s Department of Global Health, told Time, “There is a growing body of scientific literature that is identifying this link between climate-related factors and adverse mental health outcomes. And every indication is that as the climate change continues to worsen, these links will gain in strength.”

There are a “multitude of interrelated psychological, social and biological factors ranging from disrupted sleep to the heat-impaired function of vital neurotransmitters and hormones” when understanding how heat impacts brain function, per Time.

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How does extreme cold affect your brain?

Low body temperature due to cold environments can cause unclear thinking and limited body movement, which could spur confused thoughts or irregular responses, according to the Wisconsin Department of Health Services.

The National Library of Medicine conducted a study that found even one quick exposure to the cold can “impair attention, speed of processing, memory and executive function,” depending on the individual's physiological response, the temperature reached and duration of time spent in the cold.

The BBC previously reported that cold temperatures can slow blood flow to the brain, which means tasks take longer to complete in colder climates.

Professor Damian Bailey of the University of South Wales told BBC that when you’re cold, “you’re delivering less blood to the brain, so there’s less oxygen and less glucose (sugar) getting into the brain and the downside of that is it’s having a negative impact on your mental gymnastics.”

Professor Akiko Iwasaki, an immunobiologist from Yale University, told BBC that immune response becomes less active in colder climates.

“The evidence clearly suggests that cold is more deadly than the heat, there are a higher number of deaths caused through cold snaps than there are through the heat snaps,” Bailey told BBC.

To find information on how to prepare against and recover from severe weather, visit https://www.cdc.gov/disasters/index.html.