“The explanation for how it works is that in order to sleep, we have to expel internal heat to the outside through vasodilation,” says María José Martínez, coordinator of the Chronobiology group at the Spanish Sleep Society (SES).

For example, the human body functions like any other machine that, after a long day, overheats and, in order to rest, needs to “shut down” or “air out.”

Regarding this scientific process, Martínez explains to Cuidate Plus: “What we do is lower the internal temperature of our organs by dissipating heat outward through vasodilation. That is, the blood capillaries open, increasing our peripheral temperature in the skin, hands, and feet.”

It’s precisely when this vasodilation occurs that we tend to stick out one foot to expel that heat.

“We can observe this phenomenon very clearly in babies. When they’re sleepy, we see that their ears and nose are red and warm. What’s actually happening is that they’re vasodilating the peripheral areas to expel excess heat and be able to sleep,” the professional points out.

This is why this vasodilation, which regulates body temperature and allows us to rest, takes place in the peripheral areas of the body.

Tips for better sleep