Our sleep is affected by summer in general and light and heat in particular. We get more light and it turns off the sleep hormone melatonin. The high temperatures also shorten sleep. Therefore, it is perfectly normal that we do not sleep as long in summer as in winter. Evolution has simply arranged it so that we do not need as much sleep during the bright season. The idea is that we should instead be active and cultivate our land.
– In summer, we sleep on average half an hour less per night than in winter, says Christian Benedict, associate professor of neuroscience at Uppsala University and scientific secretary of the Swedish Association for Sleep Research and Sleep Medicine.
The temperature controls sleep
When it’s time to sleep, our biological body clock talks about it by lowering body temperature.
– But now, when it is so hot, the body has a harder time lowering the temperature in the evening. The vessels in the hands, feet and face, which normally dilate and release heat, can not make it as easy as usual.
The heat delays the body’s signal that we should sleep until it gets cooler, which can take a long time after our normal sleeping time.
– This sleep pattern is something we have to get used to. We will sleep even less in the future as climate change raises the temperature, says Christian Benedict.
He says that new calculations have shown that we will probably sleep 50 hours less per year until 2100 compared to today.
Changed routines
– Some researchers who have looked at this believe that 50 hours is an underestimation and that our sleep pattern will be even shorter.
To sleep better and longer, you can help the body on the stack when it comes to lowering the temperature. This can be done in several ways.
– Many people have a holiday now and that means that you change your routines and eat dinner later and drink more alcohol. A heavy and late meal and alcohol disturb sleep, says Christian Benedict.
Instead of resting, the gut is allowed to work night shifts. If you have also drunk, there is a risk that you snore more and sleep more restlessly.
– You can also create better conditions for sleep by turning off light and heat from the bedroom even during the day. Then the room does not heat up as much. If you are going to air, do it early in the morning or late in the evening.
Do not sleep naked
Christian Benedict is not a supporter of the sleep-naked trend, which is said to provide better sleep. He thinks that you can use a thin blanket or duvet cover in cotton, linen or silk, despite the heat. It may sound like a paradox, but sleeping naked can increase the risk of catching a cold in the middle of the heat wave:
– If you sleep completely naked without anything, you run a greater risk of the body becoming hypothermic, especially now when you sweat a lot. When the sweat evaporates, the skin cools down and this can increase the risk of colds and stiff muscles, he says.
You can also sleep better by taking a hot shower in the evening.
– It is better than an evening dip because the cold contracts the vessels so that they do not let out the heat. On the contrary, a hot shower opens the vessels and lowers the body temperature.
Exercise late in the evening raises the body temperature and should therefore be avoided.
– But above all, I want to say that you should not worry about sleep too much. We manage sleep deprivation for a period and you can rest even if you are in bed without being able to sleep, says Christian Benedict.