During summer heat waves, you know your body will be hot and sluggish. But did you know that your brain is affected by the heat too?
Two new studies show how heat waves and temperature spikes – which are expected to become more frequent due to climate change – are impacting our lives in surprising ways.
In a new study by Harvard University, researchers found that extreme heat makes it harder to think! The study was published in the July 10 edition of PLOS Medicine as part of a special issue on climate change and health.
In the study, researchers tracked 44 students living in college dorm rooms during the summer of 2016. About half of the students lived in air-conditioned buildings, while the rest lived without AC.
Over 12 days – including a five-day heat wave – students took two tests each morning just after waking up. One test measured students’ cognition and their ability to focus. The second test measured how quickly students processed and memorized information.
The findings showed that during the heat wave, students who lived in the heat performed significantly worse than those who lived in air-conditioned dorms.
The overheated students experienced decreased test scores across five measures, including reaction times and memory. Students in air-conditioned rooms were not just faster, but also more accurate.
According to the Harvard study authors, future studies are needed to better understand how heat-related stress could impact larger populations, including the ability to learn, economic productivity and workplace safety.
The second study, conducted by Stanford University professors and published in the July 23 edition of Nature Climate Change, suggests that hotter temperatures – a result of the changing climate – are leading to more suicides. The study used new methods to understand the relationship between temperature and suicide and depression.
The Stanford study found that a one-degree Celsius increase in average monthly temperature correlated with increases in the monthly suicide rate in the United States and Mexico. The study projects that unmitigated climate change could result in a combined 9,000 to 40,000 additional suicides across the United State and Mexico by 2050!
These studies add to a growing body of evidence showing how heat affects our thinking and our mood. Here are a few others:
- A 2006 study from researchers at Lawrence Berkeley National Lab found that when office temperatures rise above the mid-70s, worker performance go down. Worker productivity peaks at about 72 degrees.
- A study of high school graduation exams in the New York City public schools found that taking test in hot weather reduces passing rates.
Scientific American just released a new animation, “Temperature Circle,” depicting a century of global warming in just 35 seconds. Bars representing 100 countries’ annual average temperature anomaly – blue for abnormally cold weather, red for abnormally warm – pulse up and down as 100 years pass. And, yes, the circle ends up “in the red.”
To view the Scientific American animation, go to https://www. scientificamerican.com/ article/a-century-of-global- warming-in-just-35-seconds/.
To read the new Harvard study in PLOS Medicine, go to http://journals.plos.org/ plosmedicine/article?id=10. 1371/journal.pmed.1002605. (PLOS is Public Library of Science.)
To read the new Stanford study in Nature Climate Change, go to https://www.nature.com/ articles/s41558-018-0222-x .
And to learn more about preserving New Jersey’s land and natural resources, visit the New Jersey Conservation Foundation website at www.njconservation.org or contact me at info@njconservation.org.
Michele S. Byers is executive director of the New Jersey Conservation Foundation in Morristown.
