 That is partly, in fact, due to their smaller size without getting into a lot of science there. But it also can help because neither of them can sweat. They cool through indirect means. So dogs will pant and then cats will most likely find somewhere cool to lay down. Usually that's why you'll see cats spread out on concrete or in the shade on cool grass, things like that. Mostly talking about outdoor cats right now because those are the ones we've got to worry about.