Most of SIDI's footwear incorporates a lot of plastic in their construction. During the construction process heat is used to bend, shape, and mold some of those into the shapes they need to be. When you place your boots or shoes next to an intense heat source like a fire or a space heater they can warp critical components out of shape or weaken their integrity.
The best way to dry out your footwear is with paper. Newspaper works best. Simply gather up as much as is needed and pack the boot or shoe to a medium density with newspaper. Set them in a cool dry place for an hour or two and let the paper do it's work.