Maybe YOU all figured this out eons ago, but dummy here just did.
I'd done the stove top part of a Shepherd Pie in the middle of the afternoon ( had an errand to run tween 4 and 5 ) and there it sat, warm and oven ready. I didn't want to stick it in the fridge to cool off and then take forever to bake. Didn't want it to sit on the counter too long either and get to room temp.

BONG!! I whipped out my Anchor Hocking casserole tote, heated the gel insert in the mike, wrapped the cass in a towel, and put it and the hot insert in the tote, zipped it tight, and covered it all with another towel.

Two hours later, it was still quite warm and ready for the oven. I don't think it'd reached an unsafe temp,-- at least no sign of food poisoning yet. HTH.