Humans perspire, of course, in warm weather to expel excess heat. And dogs don’t sweat; but rather keep their mouths open and pant to exhale moisture-laden air.
But when we had a dog, we also had a cat–and he didn’t do that, although he had a thick fur coat (he was colored like Socks) year round. How do cats (whose body temperature, like dogs’, is 3 degrees higher than a human’s)?
Dogs sweat through their feet if need be. On hot days you may see wet paw prints from your pet.
Same with cats, complete with leaving wet footprints. They also self-regulate through licking their fur and letting it evaporate.
Cats will pant, but usually only when really overheated. One of my cats used to play so hard when he was a kitten that he would actually start panting, which was a sign to immediately stop the playing. Unlike with dogs, panting cats are usually overstressed cats.
Remember dogs are bred from more cursorial predators, cats from more ambush predators. Dogs probably have a greater native capacity to shed heat, because their ancestors spent more time obligately on the run. Domestic cats by contrast would have the luxury to avoid that kind of continual stress and beat the heat behaviorally.
I came to say this. Cats do pant, just not as commonly as dogs. Mostly, they stay cool by refraining from activity and seeking cool resting spots.
Yeah, cats IIRC originated in northern Africa and like things really warm. We once had a cat who on stinking hot summer days would go up in the attic, which was easily 10 degrees warmer than the rest of the house and had no ventilation to speak of.
Since Tamerlane nailed it in the first response, I’ll continue with the anecdotal example type thing. One of my cats is a little heat-seeking missile. She will squish herself under a radiator at every opportunity, and when my radiators are on, they’re way too hot to touch. I’ve pulled her out when she was sleeping before, worried that she was sleeping through getting burned or something, and her fur was HOT. She just looked at me like I was crazy and curled back up in the same spot. She also presses herself up next to the oven when it’s on and won’t move when I open the door, she just ducks a little and lets the heat from under the door wash over her. I’m sure if my fireplace was still operable and I used it, she would manage to set herself on fire. Cats just tolerate/like heat better than most people and dogs.
Well, Archie had his “jungle”–a small bush across our driveway where he would hide, to relax, and to stay cool, along with having a respite from those silly humans and that dumb dog. 