Some very good ideas here. On days that we've had pizza for lunch at work, I've taken the leftovers home using a method similar to what "No Exit" described. But, I think that could get quite messy with a fresh out of the oven pizza. I guess I'll never know until I try though. The Reflectix insulation sounds very promising. I might give that a try before dropping $40 on a premade bag that might not work as well as advertised.