The temperature of Heaven can be rather accurately computed from available
data. 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 seven times seven (49) times
as much as the Earth does from the Sun, or fifty times in all. The light we
receive from the Moon is one ten-thousandth of the light we receive from the
Sun, so we can ignore that. With these data we can compute the temperature
of Heaven. 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 fifty 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 (~300K), gives H as 798K (525C). The exact
temperature of Hell cannot be computed, but it must be less than 444.6C, the
temperature at which brimstone or sulphur changes from a liquid to a gas.
Revelations 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 means that its temperature must be at or below the boiling point,
or 444.6C (Above this point it would be a vapor, not a lake.) We have,
then, that Heaven, at 525C is hotter than Hell at 445C.
-- "Applied Optics", vol. 11, A14, 1972