Notably, very few studies have explored the change in sedimentation distance with ambient temperature. The vapour pressure of water is strongly dependent on temperature and this impacts on the compositionally dependent vapour pressure of saliva and deep lung fluid droplets. In addition, the ambient temperature also impacts on the buoyancy of the respiratory jet. At warmer temperatures the jet is less buoyant and carries the entrained droplets greater distances. We compare droplet evaporation-sedimentation profiles for 60 m diameter droplets at 50% RH and temperatures of 273 to 303 K at 5 K intervals in Fig 6a . Hygroscopic response is only very weakly dependent on temperature, so we assume that the hygroscopicity measurements reported earlier are temperature invariant. At the lowest temperature, the droplet sediments ~1.85 m from source, evaporating to an equilibrated diameter of 16.8 m. At elevated temperature, the vapour pressure is higher and the droplet evaporates more rapidly, This, combined with the reduced buoyancy of the respiratory jet, contribute to carrying the droplet further and increasing the sedimentation distance. At 293 K, the droplet sediments at ~2.9 m. As an indicator of the sensitivity of the sedimentation distance to temperature, we report the change in sedimentation distance when the temperature is 303 K (