Climate change is keeping Americans awake at night. Literally.
By 2015, a wave of heat swept Southern California. At that time, Nick Obradovich was a graduate student at the University of California at San Diego. During the day, he said, everyone in college became slow and grumpy.
The sunset brought little relief. “For a number of nights in the heat wave, I was lying in bed with plenty of time to think,” said Obradovich, now a member of Harvard’s Kennedy School and a researcher at the Institute of Technology’s Media Laboratory Of Massachusetts. He wondered if anyone had studied the relationship between sleep abnormalities and temperature.
Scientists have observed a bad break in hot laboratory environments and suffocating homes. But with respect to Obradovich, he told The Washington Post that no one had taken many beds in their homes in the United States. Obradovich decided to investigate. As he and his colleagues noted in a study published Friday by Science Advance, researchers relied on a survey of disease control and prevention centers representing 765,000 Americans contacted between 2002 and 2011 for the entire United States.
The CDC recounts Americans at random to learn about their place of residence, income, age, consumption, seat belt, if they were sunburned recently and other public health problems. The interrogeurs also wonder how insufficient sleep nights they had in the last month. The study authors have gained these responses with weather station records to determine if respondents have been exposed to unusual nighttime temperatures.
With this information, the researchers calculated that each 1 degree Celsius night temperature increase produced three additional nights of non-restorative sleep for 100 people per month. Scale in the United States, the authors wrote that this bump grade 1 translates into about “110 million additional nights of insufficient sleep” each year.
“This is an interesting and important study that shows the relationship between warm temperatures and sleep quality and the expected impact of climate change in this situation,” said Joris van Loenhout, an expert in environmental health at the Catholic University of Leuven in Belgium , Which has not participated in this report.
Physiologically speaking, this loss of sleep is logical. Then the body cools as we prepare to nod. Our blood vessels grow, allowing heat to escape more quickly our body. Body temperature fluctuating around 1 degree for 24 hours, will be lower in the early hours of the morning.
“Decreasing body temperature is one of the strongest signals in our brain to cause sleep onset,” said Sara C. Mednick, a sleep psychologist at the University of California, Riverside and co-author of the study. “This decrease in temperature is regulated in part by ambient temperature,” he said. “Therefore, when the ambient temperature is too high, the body may not cool and therefore can not fall asleep.”
Scientists sleep hackers could recommend to stick a foot or two blankets away to help this heat exchange. But sometimes an exposed foot is not enough. This is why in the middle of the heat waves, we will turn on conditioning.
Given the ubiquity of air conditioning, Obradovich said he hoped to find a less pronounced effect. “The United States is a rich country on average and a fairly temperate countries,” said he was able to use climate control technologies to relieve hot weather spikes. He said countries like Brazil and India would probably be worse, but scientists do not have the data.