I usually love summer & winter best of all, but both have to do with being outside. Stuck inside is miserable.
Less miserable, stuck unable to go do anything, in summer... Mostly has to do with keeping my hair wet (personal air conditioning*), well hydrated (if I'm not peeing clear once an hour, I drink more, making sure to include sweet teas/coffee, pinches of salt, etc.), & my mind active / engaged.
For true heat, I greatly prefer soaking underarmor/skinz/similar and wearing them under my clothes / ideally something loose & flowing, so that my movement creates breeze even in heavy/calm air. Extreme heat I also pack my bra with ice, to melt and continually dampen my under things. Filling a bathtub with cold water and soaking periodically also helps. A fan blowing across a bowl of ice. Cold foods or very very spicy foods. If you drink alcohol, hydration becomes even more important, but the dilating of blood cells helps release a lot of body heat, as well.
TBH, though, the single best cure I know of for heat is to go out in it. Stay very very very hydrated (weakness/flagging, headaches, dizziness, flushed, confusion, & irritation generally follows dehydration. If you're thirsty? You're dehydrated. Drink before you're thirsty.), cool off from time to time, but being out and moving for even short periods of time helps acclimate. After a few days you can do for an hour what you couldn't do for 5 minutes. After a week or two you can do it all day. But when too sick/injured to acclimate? Improvisations are just durn useful.