Sounds similar to the Hot water & Cold windshield rule right? It's because it's the same rule.
Unfortunately I wasn't thinking today while I was trying to start my second round of cleaning by boiling for the residue ridden 5 gallon. The apartment has been cold all day and I didn't stop to think that the tank would be cold too.
I fill the bottom with boiling water, turn around for 15 seconds then hear a crack.
I check under my shoes because it sounded like I'd stepped on a cracker but then I hear running water. Then I turn to find my tank leaking all over the kitchen divider and a huge crack that spans almost the entire front of the tank.
Fortunately I'm picking up my sister's spare tank on Tuesday because she has a 5, a 10, and a 15. All empty. I'm taking her 5 because she's gonna start up her 10 soon.
So yeah. For all my fellow dim and dull crayons out there take head of my stupidity and pour warm water, then hot, then boiling water in your tank IN THAT ORDER if you're boiling it to clean it in during the winter.