I have seen the "food" stay hot things (not going to say "Thermos" because I can't remember if it was that brand or not), at outdoor stores, and probably Target/Big W/Kmart. Coming into the cooler weather, most stores should be well stocked of them.

Just wanted to say that I bought a Thermos (brand drink holder thing) last year at an op shop, and it's super old! Okay, it doesn't have a cork, it has a screw top, but its still old. I used it yesterday (amongst other times), for coffee. That was sometime in the morning (I preheated it with hot water), and the boys didn't open it until 5pm. The coffee was still steaming hot! Go Thermos! I never knew they kept hot that long!