Students of mythology will recollect that the second Labour of Hercules was to fight Lernaean Hydra, a nine-headed monster with the endearing habit of growing two ferocious heads to replace each one that was cut-off. Autres temps—conventional cigarettes may be on the way out as legislators (although some rather reluctantly) have tightened the noose, with a rich yield of health benefits for children,1 2 but the new Hydra-head of vaping and other means of inhaling nicotine have come on the scene. Far from being given the Hercules treatment (a burning firebrand on the neck stump of the severed head), they have been enthusiastically embraced by Public Health England,3 Members of Parliament and others as ‘at least 95% safer than cigarettes’,4 and proposals to allow vaping in public places are being advanced. By contrast, the European Respiratory Society5 and the Federation of International Respiratory Societies6 among others7 have come out strongly against their use. How should those who care for the respiratory health of children react? Are e-cigarettes the health benefit that their protagonists suggest, or an emerging and sinister threat to lung health?