My cousin studies in a town located at almost three hours drive from his home. His mom frequently sends him home-cooked food through some bus service which runs between the towns. She places the food in a food container. In summer, she first freezes the food then places it in the container. But the bus staff is careless in handling of such food delivery because it's not part of their business and as a result the food starts de-freezing before reaching the destination. It spoils the quality and flavor of the food. Do you have any better idea which can help her? Isn't using a 'hot pot, a good idea?