Smokers turn to e-cigarettes to ease nicotine withdrawal, or to avoid harmful chemicals in tobacco smoke. But many use e-cigarettes in public spaces and regular cigarettes everywhere else. Quitting half-way won’t help. And researchers do not know that smokeless vapor is safe. E-cigarettes create an inhalable nicotine vapor by heating a liquid nicotine solution. While there are many different e-cigarette devices on the market, the basic parts of a typical device include a battery, a cartridge with nicotine (and possibly flavoring), and a heater that vaporizes the nicotine to be inhaled.