How to Keep Food Hot in Thermal Food Containers
1) Preheat an insulated food container for 3-5 minutes with boiling water.
2) Warm up the food (the hotter the food the longer it will stay warm in the food container).
3) When the food is warmed up, pour out the hot water and fill the container right way (do not overfill).
4) Put the lid on and place the container in a lunchbox (optional).
5) Tip: make sure the container is as full as possible. If there is empty space, the food will cool down faster.
6) Liquid food will stay hot longer than solid food (according to the law of physics).