An observation about our cats
After we'd done this for a bit, I looked at him, and said to Lis, "Could you feel his ears? Are they warmer than usual?" She touched them, and said, "Yeah -- feel them." Yep, it was clear that he was dumping excess body heat out of his ears.
They were not only radiating heat, but, when we looked at them more, they were so pink from extra blood flow that they were almost glowing.
If we get our cat all revved up, his ears glow.
That's pretty nifty, I think.