When it comes to bedtime, everyone has their own routine — the perfect pillow, the right mattress, total darkness, or perhaps some white noise. But there’s one surprisingly common habit many people share: sticking one leg out from under the blanket to fall asleep.
It might seem like a random quirk, but there’s actually a scientific reason behind it — one that has everything to do with how our body regulates temperature.
The Science Behind the Habit
According to María José Martínez, coordinator of the Chronobiology Group at the Spanish Sleep Society (SES), this behavior helps the body cool down — a key process that allows us to fall asleep.
“To sleep, our body needs to release internal heat through vasodilation,” Martínez explains.
Just like any machine that overheats after running all day, the human body also needs to “cool off” before it can rest.
When bedtime approaches, our internal temperature must drop slightly. The body achieves this through vasodilation — when blood vessels near the skin widen, allowing heat to escape more easily. This causes the hands, feet, and skin to feel warmer as the heat moves outward.
That’s exactly why we instinctively stick one foot out of the blanket — to help expel that excess heat faster and reach the comfortable temperature needed for sleep.
Martínez adds an interesting observation:
“You can see this very clearly in babies. When they’re sleepy, their ears and nose turn red and feel warm. That’s vasodilation — their bodies are releasing heat so they can fall asleep.”
In short, letting one foot breathe isn’t just a comfort preference — it’s a clever, automatic response by the body to help regulate temperature and transition into rest.
Tips for Better Sleep
Even if your “one-foot trick” helps, several other habits can improve sleep quality. According to the Mayo Clinic, here are science-backed ways to get better rest:
1. Stick to a sleep schedule.
Aim for at least seven hours of sleep each night, and try to go to bed and wake up at the same time daily.
2. Watch what and when you eat.
Avoid going to bed hungry or overly full. Heavy meals late in the evening can make sleep harder.
3. Create a peaceful sleep environment.
A cool, dark, and quiet room is ideal. Use blackout curtains, earplugs, or a white noise machine if needed. Limit screen time before bed — light from phones and TVs can delay sleep.
4. Limit daytime naps.
Long or late naps can interfere with nighttime rest. Keep naps under an hour and avoid them in the late afternoon.
5. Move your body.
Regular physical activity helps you fall asleep faster and sleep more deeply. Just avoid vigorous workouts right before bed.
6. Manage stress.
Try to resolve worries before bedtime. Journaling, deep breathing, or meditation can help you leave your stress outside the bedroom.
So next time you find yourself poking a foot out from under the sheets, remember — it’s not just a quirky habit. It’s your body’s built-in cooling system, helping you drift into a deeper, more restorative sleep.