As Five continues to explain, Strange looks a bit confused. He has so many more questions about this that he's not entirely sure Five can answer. Why do the vents need to be so big? How can you get inside them, are they on the floor or something like that? Where does the hot air come from in the first place and how exactly does one get the air to move?

Of course, the answer to the last question in Strange's mind is 'magic'. But it would be silly to have a magician for the sole purpose of heating a building.

He frowns for a moment, mulling over his questions, before Strange asks, "But wouldn't you be hot or cold yourself if you crawled around in the vents?"