Insomnia and sleep problems aren't normally something we would talk about on a podiatrist blog, but in this case it makes a ton of sense: studies show that your feet have a surprising impact on your ability to get a good night's sleep.
By keeping one foot, or both feet, outside of your blanket, you can sleep better and fall asleep faster. Why? It's a cooling trick to get your body temperature down, which normally happens automatically as you begin sleeping. By forcing the cool-down period to occur faster during a time that you normally go to sleep, you're essentially tricking your body into thinking it's already entered into the cool-down state associated with sleeping. 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. By sticking a foot out or taking a bath before bedtime, your temperature will drop accordingly.
So why your foot, and why do so many people do this already without even thinking about it? The skin surfaces of both our hands and feet are unique in that they’re hairless and because they 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.
Obviously this doesn't cure insomnia for everyone, but it's fascinating that the humble foot can have such a big impact on the rest of your body- of course, as podiatrists in foot surgeons, we already knew that. :)