The top of the iguana's cage is screen, on the screen it has many heat lights, as she needs them to survive. The cats have gone on this screen before and knocked a heat light down that was on. If I wasn't home and they did this - the house would be no longer and they'd all be burnt to a crisp.
I agree that the cats shouldn't be in the garage - that's why I'm moving them into my room.
The cats always scratch on the garage door when they want out and they have quickly learned that when they do that, they'll get what they want. Since the weather is starting to get warmer, I will let them out on the screened in back porch for a while.
That's the whole idea of this move - to make their lives better.