Sluggish Brain? Blame It on the Summer Heat


If the summers get hot and humid where you live, you’re probably familiar with feelings of lethargy during a heat wave – the sense that you just can’t do a thing until you get into the air conditioning. But did you know that high temperatures can also slow down your ability to think?

Even young, healthy adults are susceptible to brain changes brought on by spiking temperatures, suggests researchers at the Center for Climate, Health and the Global Environment at Harvard University in Cambridge, Massachusetts. Their study involved college students living in residence halls during a summer heat wave. Half of the students lived in air-conditioned dorms where the temperature averaged 71 degrees, and half lived in dorms without air conditioning where the temperature averaged about 80 degrees.

Study participants took two tests, one that measured cognitive speed and memory and one that assessed attention and processing speed, every day for 12 days. According to the researchers, those in dorms without air conditioning had slower reaction times overall and scored 13 percent lower on basic math tests, with an almost 10 percent lower number of correct responses per minute than those in dorms with air conditioning. This study helps confirm earlier research showing the effects of heat on mental performance.

Sourced from: PLOS Medicine