Study hints at sleep disturbances due to climate change
Sleep, an essential, restorative process for human health and productivity, can be disrupted by warmer temperatures associated with climate change. According to a study by researchers from the University of Copenhagen, Denmark, extreme weather events affect daily human activities – increasing surrounding temperatures negatively impacting human sleep is another cause for concern.
Hot days are known to increase the amount of hospitalisations and deaths. Hot weather has also been suggested to influence sleep quality as of late, but how temperature fluctuations may impact changes in objective sleep outcomes in people living across a variety of global climates remains unclear.
“In this study, we provide the first planetary-scale evidence that warmer-than-average temperatures erode human sleep,” said Kelton Minor, PhD. fellow of the University of Copenhagen. “We show that this erosion occurs primarily by delaying when people fall asleep and by advancing when they wake up during hot weather.”
In analysis of global sleep data – from accelerometer-based sleep-tracking wristbands – collected from more than 47,000 adults across 68 countries – sleep declined an average of over 14 minutes on very warm nights (greater than 30 degrees Celsius, or 86 degrees Fahrenheit).
The researchers also noted the likelihood of getting less than seven hours of sleep increased as temperatures rose.
“Our bodies are highly adapted to maintain a stable core body temperature, something that our lives depend on. Yet every night they do something remarkable without most of us consciously knowing — they shed heat from our core into the surrounding environment by dilating our blood vessels and increasing blood flow to our hands and feet,” Minor explained.
But, for our bodies to transfer heat, the surrounding environment needs to be cooler than we are.
Even though most humans are better adapted to colder outside temperatures than hotter conditions compared to animals, possibly due to the greater prevalence of air conditioning in developed countries, the effect of warmer temperatures and sleep loss is unequal globally, and new research should especially consider more vulnerable populations, particularly those residing in hot and poor regions.
