Post #1554339

@transitionalaspect Do you know how temperature control in bird's feet works? It's pretty neat: the veins & arteries in the legs are right next to each other, so that warm blood flowing out of the body & into the feet heats up the cold blood flowing back the other way, giving off so much of its warmth that it doesn't have a lot to lose by the time it is exposed to the cold environment. (Heat-recovery ventilation for houses works on the same counter-flow principle!)