Global climate change is fraught not only with extreme weather events, to which we seem to have become accustomed. As scientists have recently found out, an increase in ambient temperature affects the duration of our sleep, reducing its quality. And this problem will only get worse — we have to sleep less and less.
Women and people over 65 suffer
The study was conducted by the Danes. Specialists from the Copenhagen and Danish Technical Universities analyzed the information base containing more than 7 million records of night sleep of 47,000 adults from 68 countries. The data was anonymous, they were collected from special bracelets for tracking sleep: the gadget recorded when a person fell asleep and when he woke up. At the same time, the subjects led a normal life.
In parallel, scientists analyzed information about the local weather and climate. After the data was compared, curious things turned out. It turned out that during hot nights, when the temperature outside the window rises above 30 ° C, people on average sleep 14 minutes less than on other days. For a year, as a result, 44 hours of lost sleep accumulate.
The authors of the study found that unusually warm nights shorten the amount of time the body needs to rest, primarily by falling asleep later. The problem is observed in all countries, regardless of their climate. However, there are nuances. It is especially noticeable in countries with a low standard of living or with a hotter climate, as well as among women and people over 65 years of age. The low standard of living, scientists suggest, is reflected in the provision of the population with air conditioners. Women, on average, have more subcutaneous fat than men, and it slows down the cooling process. As for the elderly, there is nothing strange here: in principle, they sleep less, and the thermoregulation of the body works worse with age.
In addition, scientists were surprised to learn that the inhabitants of tropical countries, contrary to the widespread opinion, are not adapted to the night heat better than others.
The optimal range for — from 15 to 22 °C
Lack of and poor quality sleep is fraught with a number of problems. This is fatigue the next day, and a high risk of heart disease, dementia, depression, obesity and cancer. In humans, cognitive functions and productivity decrease, the stability of the immune system is disturbed. As a result of all these troubles, life expectancy is reduced. Regular and quality sleep, on the contrary, supports physical and mental health, increasing our lifespan.
But will it still be. Sleep problems, the Danish scientists promise, will worsen as the warming continues, and nothing foretells its stop. By 2099, the increase in global temperature will lead to the fact that each person will lose 50-58 hours of sleep annually. Even with a warming of 1°C (which is a very optimistic scenario), the most vulnerable populations will suffer even more: for example, women will lose a quarter more sleep than men.
Although everyone's habits are different, there are generally accepted recommendations for optimal air temperature for sleep. She, the researchers pay attention, ranges from & nbsp; 15 to & nbsp; 22 °C. If the temperature is outside this range, your sleep will be shallow, you will wake up more often and end up not getting enough sleep. At the same time, high temperatures affect our condition more than low ones.
“Depending on the time of year, demographics, and different climates, higher air temperatures are constantly disrupting sleep. And the amount of sleep deprivation gradually increases as the temperature rises, — says Kelton Minor of the University of Copenhagen, one of the authors of the study.
“High temperatures can increase arousal and shorten the deep slow-wave sleep phase, during which the body recovers, — scientists write in an article published in the journal One Earth. — Lack of sleep impairs judgment and increases the risk of injury while driving and operating machinery. Chronic sleep deprivation increases the risk of many health problems.
Because sleep loss due to climate change will be felt unevenly around the world, further research should focus on vulnerable populations living in warmer and poorer regions of the world. Now scientists intend to continue working with specialists in sleep and climatology. This will help them clarify the identified differences.
Rate the material