It's generally not advisable to microwave cardboard food boxes. Most cardboard packaging is not designed to withstand the heat generated in a microwave, and microwaving may cause the cardboard to catch fire or release harmful substances. Cardboard boxes often have additional coatings or adhesives that can be unsafe when exposed to high temperatures.

For safe reheating, transfer the food to a microwave-safe container. Always follow the packaging instructions and look for symbols indicating microwave compatibility. When in doubt, it's better to err on the side of caution to avoid potential hazards.