I've experienced RI a few times.

I had a small break out this year but caught it at it's beginning stages. A window was left open which is by the cages, the cold air entered the vents, RI set in. I put them all into a single cage so I could monitor all temps and humidity perfectly. I cleared up the RI myselfy just got put back into their own cages today.

And you're right, it is a good feeling.