I'm not a biologist or anything, but FACT as far as I'm aware. Domesticated cats are much closer to wild cats than domesticated dogs are to wolves. They likely stem from an older version of the species that currently live in Africa, which is routinely that hot even in the shade. Their hearts just beckon back to the olden times when they were worshiped as gods, it was comfortably warm outside all the time, and they could engage in all the casual murdering of smaller creatures that they felt like.