Microwave ovens produce radio-frequency waves that cause the water molecules in an object to vibrate. This vibration causes friction, which allows the object to heat up to a temperature that can kill germs.

That's why microwaves are sometimes used to disinfect items such as a household sponge, as they are a hotbed for viruses and bacteria.

However, research has found mixed results on whether a microwave can effectively kill germs on a sponge, or even in food. Here's what you need to know.