Is the stainless steel shrink cup filled with boiling water? Is the thermos hot?

1, a thermos cup with good thermal insulation performance will dissipate heat slowly, and basically you won't feel the heat. Because the air itself conducts heat, but the vacuum layer does not, the stainless steel cup, cup body and cup cover should be double-layered, and air should be pumped between the inner and outer layers to form a vacuum. The effect of vacuumizing determines the thermal insulation performance of the cup.

2. There is a case that "the cup body is not hot and the lid is very hot", saying that the lid of this cup is not double-layered, or the heat insulation layer is not effective.