A conjugate heat transfer procedure including droplet impingement and runback effects is presented and validated against experimental data in a mist-flow heat exchanger configuration and an engine nacelle geometry. Computations include the solution of the air flow field, the prediction of water droplets motion and the evaluation of the cooling effect of the water film on the solid surface. The entire analysis is carried out using FENSAP-ICE (Finite Element Navier-Stokes Analysis Package for Inflight icing), a simulation system developed by Newmerical Technologies for icing applications. The numerical model is described, including the Navier-Stokes solution, the water thin film computation, the droplet impingement prediction and the conjugate heat transfer procedure. The predictions are verified against experimental data for different droplet mass flow rates, showing satisfactory agreement and allowing a useful insight in the physical characteristics of the problem.