The main purpose of this research is the interest in gas-liquid interfacial heat and mass transfer. The investigation is of a much broader interest because it relates to the basic problem of the interaction of a gas stream and a thin liquid film, a situation that is frequently encountered in engineering. A numerical method is presented which allows to treat the film running on a plane or cylindrical plate with an exact localisation of the gas-liquid interface. The application of this model in the case of an inclined plate shows the effectiveness by a liquid film of protecting an insulated plate from injurious effects of the hot gases. When an important hot flux is imposed to the plate, the temperature elevation can be controlled. Comparisons with numerical results of other authors are satisfying.