Background: Electronic inhalers (EI’s) are devices that are gaining enormous popularity in the US and the world. The units go by a number of different names: electronic cigarettes (or e-cigarettes) electronic vaping devices personal vaporizers (PV) electronic nicotine delivery systems (ENDS) These devices use a liquid solution (juice) which is heated to vaporize and then inhaled. Some of the liquids contain nicotine, while some merely release flavored vapor.  Nicotine levels in the liquids vary between preparations.  Tobacco is not used in e-cigarettes, though tobacco companies are investing heavily in EI’s. E-cigarettes are often designed to mimic traditional smoking implements, such as cigarettes or pipes, in their use and/or appearance, although more and more devices are designed not to imitate them, in an attempt to develop a different culture of user. In a recent edition of the Medical Letter® (Volume 54, [...]