Why is Dante hot all of a sudden?

For both these reasons, however, it is doubtful that the Purgatorio will strike a chord in readers the way the Inferno has. In this second part of the trilogy, Dante journeys to the Mountain of Purgatory, where the souls of the dead work off their sins so they can eventually rise into Paradise. This time, however, the pains are not tortures but penances: The souls in Purgatory actively want to suffer, because they know it is God's will. This is an understanding of God that even devout Christians would find hard to accept today. What's more, the Purgatorio is filled with long discourses on love, sin, and the soul, on embryology and astronomy. It is not less marvelous than the Inferno, but it is more exacting and requires greater imaginative submission to the Dantean universe. Dante's purgatory and his heaven are magnificent, but they remain essentially foreign. Only his hell seems less like fiction than history.