I rarely wear shoes when not outside and will be bare foot as much as possible (so I have Hobbit feet). I do have Raynaud's though, so have made to wrap up a bit warmer these days.
"Vasodilation occurs in superficial blood vessels of warm-blooded animals when their ambient environment is hot; this process diverts the flow of heated blood to the skin of the animal, where heat can be more easily released to the environment. The opposite physiological process is vasoconstriction. These processes are naturally modulated by local paracrine agents from endothelial cells (e.g., nitric oxide, bradykinin, potassium ions, and adenosine), and by the autonomic nervous system and the adrenal glands, both of which secrete catecholamines, such as norepinephrine and epinephrine, respectively.[6][7]"
It's the opposite of vasoconstriction, which occurs when you're cold and your extremities have less blood flow to prioritize the warmth of your core organs.
I learned about vasodilation in the medical tent at a music festival, finding out that high grade cannabis causes it in some people. 10 minutes after I hit a pipe, I passed out….. and stayed out