Bodies cool down while we prepare to nod off. Our blood vessels expand, allowing heat to escape our bodies quicker. Body temperatures, which fluctuate by about 1 degree over the course of 24 hours, will bottom out in the wee hours of the morning.
People tend to sleep best in colder rooms, between 60 and 67 degrees
Sleep researchers know that right before you fall asleep, your body temperature starts to drop; in the deepest stages of sleep, your body is at its coolest, about one or two degrees below normal. Some scientists believe cooler temperatures cause sleepiness, and although the pre-slumber cooling process happens naturally, there are a few things you can do to help it along:
Take a warm bath right before bed. When you leave the tub, your body temperature rapidly cools, triggering that sleepy feeling.
Drink a warm beverage – works the same way as a warm bath.
Turn on a fan.
Stick your foot out of the covers.
But why the foot, specifically? The skin surfaces of both our hands and feet are unique – they’re hairless and contain specialized vascular structures that help with heat loss. Specifically, the hands and feet contain blood vessels called the arteriovenous anastomoses, which — coupled with the lack of hair on the bottoms of your feet — are perfectly designed to help dissipate body heat.