Prompted by many requests and a recent incident, I take a look at the science behind electronic cigarettes. References: 1. Electronic cigarettes and thirdhand tobacco smoke: two emerging health care challenges for the primary care provider Int J Gen Med. 2011; 4: 115–120. www.ncbi.nlm.nih.gov 2. Effect of an electronic nicotine delivery device (e-Cigarette) on smoking reduction and cessation: a prospective 6-month pilot study BMC Public Health. 2011; 11: 786. www.ncbi.nlm.nih.gov 4. A clinical laboratory model for evaluating the acute effects of electronic "cigarettes": nicotine delivery profile and cardiovascular and subjective effectsCancer Epidemiol Biomarkers Prev. 2010 August; 19(8): 1945–1953. www.ncbi.nlm.nih.gov 5. FDA website: Public Health Focus: Electronic Cigarettes www.fda.gov