US health authorities have linked at least 18 deaths and more than 1000 cases of a mysterious lung illness with vaping (an alternative to smoking in which users inhale an aerosol, or vapour). The symptoms include chest pain, fatigue and shortness of breath, and while doctors have not been able to establish what is causing the illness (and it has not been linked to any particular product), vaping oils containing THC appear to pose a greater risk. However, if the level of risk is not well understood by doctors, people should – for the moment – still have the right to make their own choice. The government should not impose a ban on vaping until more research has been completed.