Not sure if you’re at all familiar with the Abrahamic god, Yehweh/Jehova/Allah, or if you’ve read the Bible, but that heaven isn’t so great, either. It’s all worship and singing praises for eternity. Ew.
Those bronze-age myth-writers sure had a lot of imagination when it came to devising eternal torments, but when it came to describing their idea of eternal bliss, they really dropped the ball. 
I prefer Greek bronze-age myth writers for tales of the afterlife. "You can harvest THREE TIMES A YEAR, the weather is always pleasant, and best of all, the gods stay away! What a perfect life!"
It’s all worship and singing praises for eternity. Ew.
I'm 100% convinced Satan is actually super chill and "hell" is really the place you want to go for a good time, the Bible also only has the perspective of God is good, Satan Bad. Where's Satan's perspective?
From a fundamentalist standpoint, the vast majority of scientists who ever lived will be going to hell because they don't believe. With an endless supply of heat to provide energy, you better believe they already installed air conditioning.
Bit where would they put the heat that they pulled out of the now cooled room? If it's hotter on the 'outside' of the AC than the coils of the condenser then it has no way to shed that energy...
I think we need a hell's energy adjustment taskforce (HEAT) to address this issue. Perhaps offering free heat pumps to the surface dwellers would be a start and make for a good PR move.
In buildings. Heat pumps are amazingly efficient, and pumping hot air from inside to outside (or the other way around) is something we've been doing for generations.