The Grapevine

Heat Affects Our Brain Power, But Is Air Conditioning The Solution?

If your academic or work performance tends to suffer on hotter days, you are not alone. Harvard researchers have revealed exposure to heat can affect cognitive ability by slowing down your thinking power.

"Reduced cognitive function during a heat wave among residents of non-air-conditioned buildings: An observational study of young adults in the summer of 2016" was published in PLOS Medicine on July 10.

The study was conducted over 12 days in the midst of a heat wave in Boston, Massachusetts, during the summer of 2016. The research team tested and compared two groups of participants — 24 students who lived in buildings with air conditioning and 20 students who lived in buildings without the facility.

"Most of the research on the health effects of heat has been done in vulnerable populations, such as the elderly, creating the perception that the general population is not at risk from heat waves," said lead author Jose Guillermo Cedeño-Laurent, a research fellow at Harvard T.H. Chan School of Public Health.

Each day, the students were asked to take two tests on their smartphone. The first one measured cognitive speed and inhibitory control by asking them to identify the color of displayed words. The second one assessed cognitive speed and working memory by presenting basic math problems.

Students who did not live in air-conditioned dorms performed worse on the tests compared to those who did. On average, the former group was 13 percent slower in their reaction time on both tests.

"Knowing what the risks are across different populations is critical considering that in many cities, such as Boston, the number of heat waves is projected to increase due to climate change," Cedeño-Laurent added. But the use of air conditioning to fight the heat may, in fact, only add fuel to the fire.

The facility provides a dangerous positive feedback loop by expending energy and using coolants that are responsible for "some of the most potent greenhouse gases that humans know," he stated. Instead, Cedeño-Laurent encouraged the development of new building designs that are better suited for today's warmer climate.

Recent research from the University of Wisconsin-Madison also suggested fossil fuel-powered air conditioning may contribute to roughly 1,000 additional annual deaths by 2050. While many have encouraged alternative ways to deal with heat waves, some experts advise people to simply moderate their use of temperature control devices. 

Setting thermostats slightly higher in summer and a bit lower in winter can benefit the environment as well as our health, explained Dr. Stan Cox, senior scientist at The Land Institute in Salina, Kansas.

He also linked perfectly cozy temperatures with a tendency to overeat, making slight discomfort a healthier option. "When we’re a little cold or a little warm, our metabolism runs faster," he said.