Warm-blooded

The cold-blooded animals are all feeble breathers, and the most energetic breathers are the warmest-blooded. A mollusc, a fish, a frog, a quadruped, and a bird, represent the various stages of this correspondence.

Moreover, instead of hibernating like our northern reptiles, they [birds] are able to remain active all winter, even in arctic latitudes, so long as sufficient food is available to maintain the body. This retention of heat increases the body temperature, and implies an increase as well of the creature’s activity, so that birds in addition to being the warmest-blooded animals are at the same time the quickest and most active.

“It’s getting chilly,” the Asian chick said, maybe just to hear the sound of her own voice. […] / “Oh, I don’t know. Feels all right to me.” / “I guess you’re warmer-blooded than I am. Could I have my sweatshirt now?”

We stood there, shivering, colder even than when we had been on our horses, for horses are warmer-blooded than their riders, and one always gains heat from them.

Claire jumped from her chair and smiled the warmest-blooded smile that she could muster.

Chasseur said, “Murder is a grisly, nasty business, Jessica. The female species simply doesn’t have the genetic makeup to deal sensibly with it. Murder is a cold-blooded act. Women are, by nature, warmer-blooded than men, which is why they’re so attractive to the male of the species.”