Why are you not supposed to microwave 7-eleven coffee cups?

Microwaving 7-Eleven coffee cups is discouraged primarily because many of these cups contain a plastic lining that can leach harmful chemicals when heated. Additionally, the cups are often not designed to withstand the heat from a microwave, which could lead to melting or deformation. This can create a safety hazard, as the contents could spill or the cup could break. It's generally safer to transfer the coffee to a microwave-safe container before heating.