You’ve probably done it a thousand times without even noticing — slid one foot out from under the covers to cool off during the night. But this instinctive habit is more than just a quirky comfort move. According to researchers, it may actually be one of the easiest and most effective ways to help your body drift into sleep faster.
So why does the “one-foot-out” trick work so well? The answer lies in how your body naturally cools itself before sleep — and in the surprising role your feet play in the process.
How temperature and sleep are connected
As evening sets in, your internal clock begins preparing your body for rest by gradually lowering your core temperature. This drop isn’t random — it’s a key part of the circadian rhythm and is essential for falling into deep, restorative sleep.
“The temperature drop starts about two hours before bedtime, lining up with the release of melatonin,” the Sleep Foundation explains. “Throughout the night, your core temperature continues to fall, hitting its low point in the early morning before warming up again near sunrise.”
During this cooling phase, your body pushes heat away from your core and toward the skin’s surface — especially into your hands and feet. When those extremities encounter cooler air, they act as tiny radiators, releasing warmth and helping your body shift more smoothly into sleep mode.
Why your feet are perfect heat coolers
Your feet (and hands) have an abundance of special blood vessels called arteriovenous anastomoses. These vessels allow warm blood to move directly to the skin’s surface, bypassing the usual capillary routes. This makes your feet especially good at dumping excess heat.
So when you leave just one foot outside your blanket, you’re creating a simple, self-regulating cooling system — like opening a small window in a warm car. It doesn’t take much, but it makes a big difference.
Sleep researcher Natalie Dautovitch explained to New York Magazine, “It’s likely a way of cooling down the body after it gets too warm for restful sleep. Exposing a foot might help bring you into a deeper, more refreshing sleep.”
Why one foot out can help you fall asleep faster
Scientists use a metric called the distal-to-proximal gradient (DPG), which measures how much warmer your hands and feet are compared to your core. A higher DPG means you’re releasing heat effectively — and people with higher DPG values fall asleep much faster.
A study published in the Journal of Physiology found that participants with warmer hands and feet drifted off significantly quicker than those with colder extremities.
Letting one foot stick out increases this heat gradient almost immediately, helping you fall asleep without needing to blast the AC or toss off all your blankets.
Additional ways to encourage natural cooling
The one-foot method works well on its own, but combining it with other cooling-friendly habits can enhance your sleep routine:
• Take a warm bath 1–2 hours before bed — your body cools naturally afterward.
• Keep your bedroom comfortably cool (65–68°F is ideal), per Sleep Foundation guidelines.
• If you tend to have cold feet, warm them first with socks or a foot bath, then remove layers once you’re in bed to fine-tune comfort.
When the foot trick doesn’t help
Not everyone benefits from sleeping with a foot out. If you regularly have cold feet, poor circulation, or conditions like Raynaud’s, exposing your foot might be too uncomfortable. In those situations, warming your feet gently may help more than cooling them.
Children, older adults, and people sleeping in already chilly rooms may also need to conserve body heat rather than release it. As always, comfort should guide you — not a rigid rule.
A simple trick worth trying
The next time you’re lying awake and feeling too warm under the blankets, try slipping one foot out into the cool air. This small, effortless action taps into your body’s natural cooling system, helping excess heat escape and signaling your brain that it’s time to sleep.
Sometimes, the key to better rest really does start right at your toes!