Even facilities with smoking restrictions may not be able to escape the effects of tobacco smoke. A new study finds that people can transport thirdhand smoke into otherwise smoke-free places. Thirdhand smoke consists of volatile and semivolatile compounds that are released from tobacco smoke deposited on surfaces, including clothes and bodies. Drew R. Gentner of Yale University and coworkers used mass spectrometry to identify organic compounds associated with thirdhand smoke, including 2,5-dimethylfuran, 2-methylfuran, and acetonitrile, in a nonsmoking movie theater (Sci. Adv. 2020, DOI: 10.1126/sciadv.aay4109). Spikes in the concentration of tobacco-related compounds occurred immediately after audience arrival. Emissions of these compounds were higher during R-rated films than during family movies. The researchers posit that the thirdhand smoke components were carried into the theater on audience members’ clothes and bodies. The amount of tobacco-related volatile organic compound emissions in the theater was equivalent to the secondhand smoke produced by 1–10 cigarettes. Fresh air was continually pulled into the theater through the ventilation system, suggesting that exposure could be even higher in poorly ventilated spaces.