system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: If your whole body is hot under the blankets at night, how does sticking one leg out from under the blankets reduce body temperature enough to make you comfortable again?
gpt
One leg has a decent amount of surface area that it can cool down when it's exposed to the cooler air.

If you're wondering why one leg doesn't get cold while the rest of you stays warm, that would be blood flow. The leg and the blood in it cool down, and the cooler blood circulates through your whole body, bringing the temperature down. 

Kind of like opening one window in a warm room - the cool air that comes in the window can flow through the whole room and lower the temperature a bit.