Summer Is Actually Slowing Your Brain Down, Says Science

Heat got you feeling in a trance? It’s not all in your head, according to science.

A new study published in PLOS Medicine found that heat stress—aka when too much heat is absorbed by the body, causing extreme exhaustion—can jumble our thinking, making everyday tasks more difficult to complete.

To find this out, researchers recruited 44 university students and split them into two categories: those who lived in buildings with AC (24 students) and those who didn't (20 students). Then the researchers looked at how a summer heat wave affected the students' cognitive function by administering tests via the students' cellphones twice a day for 12 days. The tests included simple math (addition and subtraction), as well as questions that measured attention and processing speed.

The results? Whether or not a student had AC made a major difference in how well they performed on the tests. The research team found that the students who were in the non-air-conditioned buildings had slower reaction times and lower performance numbers on the elementary math tests. The number of correct responses from students in non-air-conditioned buildings also drastically decreased. In short, the heat wave got the best of them and their critical thinking skills.

So if your instinct is to deal with a heat wave by staying indoors, even if you don't have AC, you may want to rethink your approach. "We all tend to think we can compensate, we can do just fine," Joe Allen, co-author of the study and co-director of the Center for Climate, Health, and Global Environment at Harvard University, told NPR. "[But] evidence shows that the indoor temperature can have a dramatic impact on our ability to be productive and learn."

While this study only looked at university students in their living spaces, it would be interesting to see these findings replicated in other environments where heat can negatively affect productivity, like schools and offices—especially as temperatures continue to rise and affect our health, thanks to climate change.

In the meantime, if you find yourself extra spacey this summer, it might be worth seeking out a cooler environment—whether it's inside or outside—and then returning to the task at hand.