I bought myself a food flask, 500ml. Doesnt keep the food as hot as I would like, but warm enough to enjoy. Im experimenting with various home made and bought meals, and how to keep them hotter. I pre warm the flask and heat the food in the microwave without burning it. Ive seen one that can be used in the microwave, hopefully the food would be hotter after several hours. My day walks dont warrant a stove, usually 7 - 8 hours.