You know, I need a whistle or something, the way I'm MMQ-ing this. (Oh, wait, that's not the quarterback; that's the ref. Quarterbacks say "Hike!")
I suppose "we have to be sure they're not on the burner while it's hot" would be similar info but more about the "cool off/warm up" period.
But, I just think that since they're metal, it's good to have officially said it. If you assumed that she knew this, and it turned out it hadn't really occurred to her, or she'd had a brain fart, where would you be? Homeless, probably, or staying in a hotel during clean-up.