Microwave ovens

Microwave ovens cook, reheat, and defrost food using high-frequency electromagnetic waves, typically at 2.45 GHz, that excite water, fat, and sugar molecules and generate heat through molecular friction. They heat rapidly but unevenly, creating cold spots where pathogens can survive, so food-safety guidance stresses stirring, covering, standing time, and checking temperatures in several places throughout the food. Microwaves penetrate only a few centimeters, so the centers of thick products heat mainly by conduction. Manufacturers design microwaveable products, instructions, and packaging around these heating patterns, and consumers should follow package directions and verify temperatures rather than relying on appearance alone.