A thermos, also known as a hot water bottle or thermos, was invented by an English scientist named dewar. A second layer of silver or reflective paint was applied to the vacuum compartment to block back the heat. Plug the bottle with another stopper. In this way, all three modes of heat conduction are cut off, and the tank can keep warm for a long time. He used this bottle to store liquid hydrogen. It is widely used. Almost every family has a thermos or thermos.