Whether facing soggy fries and rubbery bread or real safety hazards, there are ten foods you should never microwave. How Microwaves WorkTo understand why some foods suffer under microwave heat, it helps to know how this time-bending appliance actually works. 10 Foods To Never Reheat In the MicrowaveNote, the USDA recommends all reheated leftovers reach 165 degrees to prevent foodborne illness. How to reheat: Reheat pizza in the oven, or better yet, the air-fryer at 375 degrees. How to reheat: Reheat hard-boiled eggs by steeping them in boiling water.