Portable thermos with blue liquid on the top lid can you keep hot food warm inside?

Portable thermal insulation box on the lid with blue liquid inside the hot food can be insulated. According to the query related public information shows that the insulation principle of the phase change material insulation box is to use the characteristics of the phase change material to realize, the phase change material in the solid state and the liquid state between the phase change, will absorb or release a large amount of heat, so you can play the role of thermal insulation or to keep cold.