[edcculus]

This seems more likely than attributing it to temperature change. A 5-10 times increase in exposure time is probably from an aperture error.
If you're printing in a cold room, start with your chems at the proper temperature, but place your trays in larger trays, which you can fill with warm/hot water to maintain the proper temperature. The warming water can be changed as it cools, and refilled to keep you at the proper temp.

I'm thinking it may be just that. The problem happened so suddenly. I was getting good results based on a test strip I initially did. I worked on one more neg, and got good results with a slight adjustment in time. On the third neg, the print didn't develop...at all. That probably makes sense, because 2-5 seconds at f8 is probably barely enough to register. I did think it was odd that my exposures were so fast too. I didn't remember them being so fast in my classes years ago.