The temperature of Heaven can be rather accurately computed. Our authority is Isaiah 30:26, "Moreover, the light of the Moon shall be as the light of the Sun and the light of the Sun shall be sevenfold, as the light of seven days." Thus Heaven receives from the Moon as much radiation as we do from the Sun, and in addition 7 x 7 (49) times as much as the Earth does from the Sun, or 50 times in all.Science is the threatning pull to a thread that can logically unravel their protective cloth. Not unlike the Shroud of Turin. Which is kind of funny to me. I remember a fundie way back in my early online days that tried to spar with me about being part of the Stanford think tank that analyzed the shroud in an effort to authenticate it, I'm sure voxie remembers him. Good times.
The light we receive from the Moon is one 1/10,000 of the light we receive from the Sun, so we can ignore that.
The radiation falling on Heaven will heat it to the point where the heat lost by radiation is just equal to the heat received by radiation, i.e., Heaven loses 50 times as much heat as the Earth by radiation. Using the Stefan-Boltzmann law for radiation, (H/E)^4 = 50, where E is the absolute temperature of the earth (300ºK), gives H as 798ºK (525ºC).
The exact temperature of Hell cannot be computed. However, Revelation 21:8 says "But the fearful, and unbelieving ... shall have their part in the lake which burneth with fire and brimstone." A lake of molten brimstone [sulphur] means that its temperature must be at or below its boiling point, 444.6ºC.
We have, then, that Heaven, at 525ºC is hotter than Hell at 445ºC.
Even my friends/loved ones who ARE devout look at these wingnuts like they're insane. Believe what you want, but have a better argument than faith if your aim is to try and discredit fact supported evidential theory.