Ice Back Splitter

This one's based on an original idea of the third SAW movie.

Bob, a simple man with a simple name. He hasn't been taking good care of his back, so it's time he learns how fragile it is. He will be tied to ice blocks shaped like the open pages of a book, connected the same way. To escape he has to suck in a boiling substance and spit in at his frozen hands to free himself. If he's too slow the book will widely open and crack his spine.