Unsurprisingly, students in the AC group experienced significantly lower indoor temperatures, humidity, and noise (because they didn’t need to run fans) throughout the 12 days. After adjusting for the learning effect, wherein students got better at the tests over time, the researchers discovered that cognition between groups was matched during the five normal days, but those without AC experienced 13.4 percent slower reaction times and received 13.3 percent worse arithmetic scores on the five heat wave days.
And unexpectedly, the difference in cognition between groups continued during the cool-down period.
"Indoor temperatures often continue to rise even after outdoor temperatures subside, giving the false impression that the hazard has passed, when in fact the 'indoor heat wave' continues," co-author Joseph Allen explained. "In regions of the world with predominantly cold climates, buildings were designed to retain heat. These buildings have a hard time shedding heat during hotter summer days created by the changing climate, giving rise to indoor heat waves."
Allen and Cedeño-Laurent conclude that in the face of increasing global temperatures, temperature-smart buildings and homes will be a necessity for public health, especially considering that Americans spend about 90 percent of their time inside.
“Our findings highlight the importance of incorporating sustainable adaptation measures in buildings to preserve educational attainment, economic productivity, and safety in light of a changing climate.”