A National Sleep Foundation poll found that “cool room temperature was one of the most important factors in getting a good night’s sleep” with four-fifths of respondents saying that it was important to them.
Also, this temperature range is the most optimal for the brain to relax and rest, said Kajimoto.
He explained that the brain is an important organ of the human body, and therefore requires other organs to provide nutrients and oxygen to it constantly. In order to protect the brain, the autonomic nervous system, which acts as a cue for the brain to obtain a stable supply of oxygen and nutrients, will continue to send instructions to various organs of the body.
When the indoor temperature is relatively high, the autonomic nerve has to continuously issue instructions, including telling the body to increase the expiratory frequency to help dissipate heat and sweat. That is why in hot summer, the more people sleep, the more they feel tired.
Therefore, Kajimoto believes that in order for the human body to get adequate rest, it must be kept cool, and the most effective way to cool the autonomic nervous system is to inhale cool air through the person’s nose.
According to Kajimoto, sleeping in a higher room temperature like 28 degrees Celsius means one needs more time to sleep in order to rest than those who sleep in a cooler room temperature.
Furthermore, registered dietitian nutritionist and certified health manager Kyle Long cited a report from Le Nouvel Observateur stating that it is easier to fall asleep when one’s body temperature is lower, and the ideal optimal temperature range is around 22 to 23 degrees Celsius.
