Do you know that Cooling Cantrip that Gastrope’ taught Jenn? That seems to work for them. My cave is about the same altitude is Tom’s. However, I actually have furniture. It took some experimentation…I tried this “mod” stuff made out of white plastic, but it tended to stick to you pretty bad.
I finally realized that metal framed chairs with asbestos upholstery and cushions worked the best.
So it’s really quite comfortable. And nicely scented!