The temperature of Heaven as described in the Bible:
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 the Earth does from the Sun, and in addition seven times seven (49) times as much as the Earth does from the Sun, or 50 times in all.
Using the Stefan-Boltzmann fourth power law of radiation (H/E)^4=50, where E is the absolute temperature of the earth ,300 degK (273+27). This gives H, the absolute temperature of heaven, as, as 798 degK absolute (525 degC).
The temperature of the Earth as describe in the Bible:
But the fearful and unbelieving… shall have their part in the lake which burneth with fire and brimstone.
A lake of molten brimstone (sulfur) means that its temperature must be at or below boiling point, which is 444.6 degC. (Above that point, it would be a vapour, not a lake.)
We have the temperature of Heaven, 525 degC
Temperature of Hell, less than 445 degC
Therefore Heaven is hotter than the Hell.
Source: Applied Optics, 11, 1972