I guess this particularly sounds a little absurd, but I often like to leave on the a/c idea for our cat, & the TV. I leave the cable on because the house is often eerily silent separate from it, & at least if he can hear the cable he might guess better. I have never liked silence, & I imagine he particularly doesn’t like it either. As for the heating & cooling, our cabin can sometimes become quite heated, & just because I’m not there, doesn’t mean he should have to suffer. I’m not usually gone that long to begin with, & so I don’t mind leaving the a/c component on for a few hours while I am away! One time when I left our home, I forgot to leave the Heating & Air Conditioning unit on for her. I was visiting some of our relatives, & our aunt became ill & fainted while the people I was with and I were there. She went to the hospital & thankfully he was fine. After I made sure our aunt was ok, it was then I remembered that I forgot to turn on the a/c machine. I started worrying about our poor kitty, & his long fur that must be incredibly hot. I knew that he was particularly fine, but I still worried. I drove back cabin to check on her, & thankfully he was okay too. The cabin didn’t guess too warm, & so that was a relief. I turned the cooling system unit back on, both for me & for her.