A mystery indeed…
[Source: Brian @ Shoeboxblog]
The feet, hands and head have special blood vessels that are used to control body temperature. With hands under the covers and head on a fluffy pillow, it is no wonder that a feet needs to be out.
(Not that I'm belittling what you're saying, just adding on) I think it could also be that, when you stick a limb out, the blanket forms gaps that allow air flow underneath, thereby cooling further.
There are no special blood vessels. They are just closer to the skin and have adequate diameter so they can contribute to overall heat loss.
yeah, but then you get killed by a monster under your bed…
Peer reviewed articles are at the bottom of the page.