Thermogram of a person using an electronic cigarette or e-cigarette. Electronic cigarettes are battery-powered vaporizers that simulate the feeling of smoking, but without tobacco. Their use is commonly called "vaping," as instead of cigarette smoke, the user inhales a vapor produced from heating a liquid substance which sometimes contains flavorings. The e-cigarette is activated by the user either taking a puff or pressing a button. The benefits and the health risks of e-cigarettes are unclear. There is some evidence which claims they can help people quit smoking but they have not yet been proven to be better than regulated medication.