Cube / Square law helps smaller animals shed heat when they need to.
Cats don't jump around as much as a matter of course. They do seek out cooler areas and lie around with their bellies up radiating heat. Cats also have a naturally higher normal body temp than humans, and maybe more than dogs.
They also are notorious for not displaying symptoms until they are really bad, your cat may be overheated and you wouldn't know it.
Make sure your animals have a choice about being cooled down and forget about it. They'll figure it out.