Literal Fire?

Is the fire spoken of literal fire? It is an accepted law of language that a figure of speech is less intense than the reality. If “fire” is merely a figurative expression, it must stand for some great reality, and if the reality is more intense than the figure, what an awful thing the punishment symbolized by fire must be.

Wm E. Evans, The Great Doctrines of the Bible, Moody, p. 262