Sleep researchers often look at something called the distal-to-proximal gradient (DPG), which compares the temperature of your extremities—like hands and feet—to your core body temperature. A higher DPG means more heat is being released from the body, and this is strongly associated with falling asleep faster.
A study published in the Journal of Physiology found that people with warmer hands and feet—and therefore a higher DPG—fell asleep much more quickly than those with cooler extremities.
Exposing one foot can raise this gradient almost instantly, helping your body settle into sleep without removing all your bedding or lowering the thermostat.
Other ways to support natural cooling
Letting one foot breathe is a simple trick, but combining it with other temperature-friendly habits can further improve sleep quality:
Take a warm bath or shower one to two hours before bedtime to increase skin temperature and trigger a cooling effect afterward.
Keep your bedroom cool, ideally between 65 F and 68 F, as recommended by the Sleep Foundation.
If your feet are usually cold, warm them briefly with socks or a foot soak, then remove layers as needed to fine-tune comfort.