When Mr. Crumrine comes to Dan's office unexpectedly, Dan quickly shovels a heated hot plate into a desk drawer. Although it is obviously hot, as we can see the glowing element, Dan seems to have no reaction or burns.
When the hot plate that Dan shoves into his desk drawer starts a fire, a sprinkler head goes off over it and begins to douse it. However, two more sprinklers are triggered, which would not happen if the fire did not spread. Sprinklers are not built to function in sequence, but only work when an element in the unit melts and opens the water valve.