Microwaves are a form of electromagnetic energy that can penetrate materials like haze, light rain, smoke and clouds, making them useful for transmitting information as in radars and speed cameras. Microwaves are commonly used for cooking food in microwave ovens, which heat only the food and not the surrounding air, saving energy. Cooking with microwaves also takes less time than conventional methods and keeps food out of the temperature danger zone where harmful microbes thrive, reducing food safety risks. However, some studies have suggested that microwaves may decrease some nutrients in foods and could potentially have harmful biological effects or increase cancer risks with frequent use.