Scientists from the International Pediatric Sleep Association, the World Sleep Society, and the University of Copenhagen warn that hotter nights are already disrupting sleep for billions of people.
As the planet warms, nights are getting significantly hotter across most of the world. Those higher nighttime temperatures are having a major effect on sleep.
Hot nights are worsening sleep for billions of people worldwide. A paper in the journal SLEEP warns the problem will get much worse if warming continues at the same rate.
Hotter regions are the least studied — and most at risk
The researchers analyzed decades of studies on temperature and sleep worldwide and found that in almost every place, climate change has pushed people to fall asleep later and sleep less.
The most dramatic finding involved the regions most vulnerable to global warming — the hottest and poorest areas. “Further warming will hit those regions hardest,” said Kelton Minor of the University of Copenhagen, the study’s lead author.
Minor pointed to recent surveys of people experiencing homelessness in Delhi, India, which showed that 49 percent of those people sleep less than four hours a night, and almost all — 95 percent — blame the heat. One respondent said, “The pavement gets so hot during the day that it stays hot all night. When we lie down, the heat seeps into our bodies and makes sleep impossible.”
“The human sleep response to temperature is this: the higher the outdoor temperature, the more sleep a person loses with each additional degree of warming,” Minor said.
The studies they reviewed badly underrepresent residents of Africa and Southeast Asia. Those regions, which already contain a disproportionately large share of the world’s current and future population, are seeing extreme temperature increases.
Modern buildings aren’t protecting people from nighttime heat
Homes tend to retain heat and don’t shield nighttime sleep from rising temperatures. What’s more, the built environment makes the problem worse, Medical Xpress reports.
“The sleep-disrupting heat inside buildings persists even after outdoor temperatures drop. The result is prolonged sleep loss that is dangerous for physical and mental health,” Minor said.
How heat-related sleep loss harms you:
- impairs cognitive function
- reduces work performance
- increases the risk of accidents
- makes people more vulnerable to illness and infection
The paper warns that if current climate trends continue, the impact of rising temperatures on sleep will not only worsen but accelerate.
