The heat may remain for some time, particularly if the candle was near a large clay pot, for example. The results of the flame remain, if the candle burned anything. The memory of the flame remains in our minds, and the concept of it can be used to light new candles. The wonder it puts into our hearts, when we see or think of a candle in a window at Christmas. The idea of it warms us, when we see candles lit for vigils. As there is hope and solidarity and love and comfort sometimes found in candles, so can a candle be found in those concepts, such is the interconnectedness of nature. All things are in all other things in a state of interbeing.

Reducing heaven and hell to physical locations serves a purpose, to encourage an accurate view of reality; just as the ideas of heaven and hell serve a purpose, to encourage us to weigh the consequences of actions, to self reflect and consider the ultimate import of the relationship between what we do and where we go. I wouldn't be so fast to reduce it to it's material nature, when nature is more than material.