In conclusion, acute vaping of PG/GLY aerosols with and without nicotine at high wattage and in large amounts induces a sustained decrement in Tcpo2 and airway epithelial injury in young occasional tobacco smokers. The latter effect seems driven primarily by PG/GLY rather than by nicotine. These intense vaping conditions also elicit a decrease in Po2 in heavy smokers. Further studies are needed to confirm these observations in dedicated vapers to shed light on the precise pathogenetic mechanisms involved, and to identify the potential long-term consequences of e-cigarette usage.