Can you make hot chocolate in a foam cup?

No, you should never heat beverages of any type in Styrofoam cups. Polystyrene is the material used to make foam cups, and it can release hazardous chemicals, such as styrene, when exposed to high heat.

Styrene has been linked to a range of health problems including cancer. Therefore, it is better to use ceramic, glass, or metal containers to heat up hot chocolate.