cherrybounce t1_j2ayzsz wrote on December 30, 2022 at 10:38 PM

Reply to comment by SirDuke6 in ELI5: Why does putting one foot out from under the blankets bring so much relief of heat while laying in bed? by SirDuke6

The feet are ideally suited to helping us keep a stable body temperature, for a few reasons.

They - like the hands - have a large surface area as well as specialised blood vessels which can be opened up to pass high volumes of blood through them and therefore offload heat quickly when required.

When not required, the blood vessels are constricted.

This, coupled with the fact that the feet (and hands) are at the end of our limbs and don't have much muscle (which produces heat) means that they cool down much more than other regions of the body.

sheevum t1_j2d18gq wrote on December 31, 2022 at 9:38 AM

This is the right answer. It’s not just about draining heat, but the key is that they can drain and regulate temperature very effectively. So sticking one foot out is enough to regulate your temperature, which it can’t do effectively when your whole body is hot. It’s an adaptive radiator when stuck out.