On the hottest days of summer, I generally just feel like giving up. By later afternoon, temperatures in my older building easily surpass whatever’s happening outside, a factor compounded by the outdated myth that “nobody needs an air conditioner in northern California.” The net effect is a feeling of tired fogginess, making concentration on just about any task rather difficult. While this may sound like a lot of whining (it is!) scientists have actually been able to quantify the cognitive hit inflicted by seasonal spikes in heat, pointing out that they take a measurable toll on all of us.
Testing the effects of living in high temperatures
Unusually high temperatures associated with heat waves have long been known to be detrimental to human health, although most research on heat has focused on cases when it’s literally a danger to people’s lives. To investigate cognitive issues possibly experienced by everyone, researchers purposely skipped at-risk populations like infants and the elderly, working only with healthy college students. In theory, any issue that would affect a 22-year-old would probably be an issue for 30- and 40-year-olds as well. The only other criteria that mattered was whether or not each student had air-conditioning in the dormitory where they lived.
Every day of the study, test participants were asked to take a few cognitive tests when they woke up in the morning. The tests included tasks like quickly reading the names of colors with letters displayed in conflicting hues, which is a long-standing way to asses how well someone can filter relevant information in a hurry. They were also asked to do some math and memory tests, giving researchers a range of performance metrics to compare. To make sure environmental conditions were also comparable, test subjects’ rooms were outfitted with temperature, carbon dioxide, humidity and noise sensors. Physical activity and sleep were also tracked with a wearable device.
Extra time and additional errors
After five days of normal temperatures, there was a spike in the area’s heat index. Almost immediately, students living without air conditioning started showing a decrease in cognitive performance. They took 13.4 percent longer in deciphering the color words, and also had 13.3 percent more errors in their math tests. Even after the heatwave broke and the outside world returned to normal, much of that heat was retained indoors, extending the impact of overheated students’ low scores.
Anyone who has lived through unusually hot days won’t be surprised by this, but anecdotally hot homes don’t help science diagnose health problems shape policy. By measuring the significant impact heat has one people’s ability to handle cognitive tasks, this study reveals that rising global temperatures may be causing more immediate and widespread problems than people realized. It’s practical to demand air conditioning for every hot home on the planet, but we may need to further prioritize heat-shedding designs in future construction, plus look for ways to mitigate possible problems caused by people too hot to think clearly.
Source: Extreme heat and reduced cognitive performance in adults in non-air-conditioned buildings by Harvard T.H. Chan School of Public Health, Medical Xpress