Global warming could cost people 336 hours of sleep a year, a study published in the journal One Earth on May 20 found.
The study’s lead author, Kelton Minor, PhD in Social and Behavioral Data Science at the University of Copenhagen, says the phenomenon is more likely to affect older people.
“It is estimated that the rate of insomnia in the elderly is more than double that of young people or people in middle age. The number of low-income people affected is three times that of the high-income group, and women are affected more than men,” said Minor.
The team also found evidence that people between the ages of 60 and 70 are the most sensitive to temperature changes. The results come from a global experiment, involving 47,600 people from 68 participating countries. All participants wore a bracelet to record their sleep habits between September 2015 and October 2017.
Within two years, the team collected 7.4 million records. They then compared the data with local weather data where the participants lived to confirm the correlation between temperature and sleep quality.
“During days when the weather is suddenly warm, the average sleep time will decrease,” revealed Dr. Minor.
Specifically, from 30 degrees Celsius or more, for every 1 degree Celsius increase, study participants will sleep 14 minutes less. The higher the temperature, the less people sleep. There are people who sleep less than 7 hours a day, they also tend to stay up late and wake up earlier. However, the team found that the human body was unable to adjust itself to a shorter sleep duration or to make up for it the next day.
“There will be no other alternative that can replace sleep. Humans need sleep just like they need oxygen, food or water. We can temporarily cope (with the heat) with air conditioning, but in low-income places, things are still very difficult,” said Kelton Minor.
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