A Seoul University scientific study has shown that people who wear socks to bed fall asleep faster and have more restful sleep than those who keep their toes exposed to the elements. Why? It's all about body temperature. For some people, hitting the sweet spot between too hot and too cold can have a big impact on the quality of their sleep. From CNET:
You're at your warmest in the early evening, between 4 p.m. and 8 p.m. When you start to feel tired, your core temperature begins to drop, which lets your body know that it's bedtime. By cooling down at this time, you can sleep more comfortably and avoid overheating at night, which can lead to insomnia or poor-quality sleep.
However, if your body senses that your feet are cold, it may try to overcompensate by increasing your core temperature — and when you're hotter, it can be harder to fall asleep.
By wearing socks at night, you'll warm up your feet and, in turn, cause the blood vessels to widen. This process is known as vasodilation and helps your body release heat through your skin, ultimately lowering your core body temperature.
Here's the study: "Effects of feet warming using bed socks on sleep quality and thermoregulatory responses in a cool environment" (Journal of Physiological Anthropology, 2018)
