tomme tippee do a travel bottle warmer but can be used for food jars/tubs ect too. i have used it for bottles and have recently started spoonfeeds so i will be using it in future too, its essentially a small flask covered with a top the height of the flask and fairly wide(although fits in baby bag no probs) but wide enought for food too so you poor hot water into this and heat food in it, arent expensive, maybe bout £10 if you are in uk