Why do we need to sleep with a blanket on even in hot weather?
It will also have happened to you on the hottest nights of the summer season to sweat but at the same time not feel exactly comfortable sleeping on your bed without a blanket or a light sheet: why, despite the heat and the clamminess, do we instinctively need to feel covered during the night even when we don't need it due to the outside temperatures? In reality there is a perfectly scientific explanation for this need, which seems more common than you think ...
via CTV News
The first explanation is purely physiological; we human beings are living creatures with a "hot" internal temperature and what our bodies do every day of the year is to regulate the difference between internal and external temperature: very simply put, if it's cold outside, we tend to cover ourselves, if it's hot outside, we find out. Yet, regardless of the external temperature, the phase of sleep is different: in this very important moment for our body, we tend to "lose control" and therefore we need external elements that help us to level and maintain the internal temperature we naturally need to be at: here's where the blankets come into play.
But there are also psychological factors that are triggered once we go to sleep, whether it's hot or cold outside. For example, we have always been used as children to sleep with at least one layer on our body, so this action over time has become both routine and mechanical; a routine that with the weight of a blanket over our body signals that after all "it's time to sleep".
The blanket or the sheet are also external factors that stimulate the release of serotonin, an extremely important hormone for regulating mood; usually when this substance is released from our body, the level of good mood and happiness rises and perhaps it is also for this reason that we prefer to sleep with a blanket to hand even when it's too hot: when we are anxious or stressed we all find it a little more difficult to fall asleep, so the almost "protective" function of the sheet helps to remove this psychological sensation and make us feel more relaxed.
Finally, again speaking of protection, the function of the blanket is also the one that has accompanied us since we were only children and had an ancestral fear of the dark; against this "invisible monster" the blanket at night was our only and most effective protection and shield against this profound terror; the years pass, from childhood we pass too early to adulthood, but certain habits are so deeply rooted in us that we cannot help but respect them every night, whether in the heat or the cold.
