A two-phase flow computer model to determine the behavior of aerosol droplets injected into a hightemperature gas environment is presented. Droplet heating, desolvation, coalescence, and transport are considered. The desolvation rate of droplets is calculated with a continuum heat and mass transport model using the Fuks correction to account for kinetic effects. Droplet transport is modeled with the Cunningham slip flow correction factor applied to Stokes' law. The direct simulation Monte Carlo (DSMC) method is used to model droplet-droplet collisions, with the collision outcome determined with the use of the Ashgriz-Poo coalescence model. The model and computational tool are applied to a spatially uniform background gas and that of an argon inductively coupled plasma (Ar ICP). We find that consideration of transitional regime effects leads to a decrease in desolvation rate, as well as smaller droplet drag. In addition, the simulation shows that droplet coalescence leads to a significant increase in the penetration depth of the aerosol even into a high temperature ICP plasma environment.