Yah, and I'd be especially concerned about sudden temperature
changes. Metal and glass expand & shrink at different rates, so extremes of heating or cooling might encourage a glass-metal CRT bond to break loose.
Extreme example: Imagine that every day I bring my roundie indoors to play for several hours, and every night I wheel it outdoors to my front porch.
Not ideal because:
1. Big temperature change.
2. Changes are sudden.
3. Hot-cold cycle is repeated often.
For long-term storage, I'd try to keep things as constant as practical, avoiding abrupt changes. Within reason, it's not like your CRT "wants" to be at a particular temperature. It's more like that scene from Wayne's World:
"We fear change!"
Phil Nelson