This mug holds hot drinks, but when it cools down, is it okay to put it in the microwave to reheat?

HITCH BICYCLE CLUB's mug has a generous allowable temperature range from minus 20℃ to 120℃, but placing it in a microwave or oven to heat it directly is not permitted^[1][2].

This product is made with a double-wall structure filled with insulation inside the walls^[3]. A double wall is a method where an air layer or insulating material is placed between two layers of inner and outer walls to slow down the rate at which temperature escapes. Generally, when such double-structure containers are exposed to microwaves from a microwave oven or radiant heat from an oven, there is a risk that the air and insulation inside the walls will expand, deforming the appearance or bursting.

While it is sufficient for directly pouring boiling water or freshly brewed coffee, when a drink has cooled down and needs to be reheated, it is best to transfer it to a microwave-safe container, heat it, and then pour it back into the mug.