The temperature fields in the center plane of a channel with a square cross-section have been measured. Steam injected at relatively low mass fluxes through a small hole in one of the walls of the channel condensed intermittently in a small area close to the inlet. The upstream temperature of the liquid cross-flow, TL, the momentum ratio, J, and the Prandtl number proved to be important for the single-phase temperature field induced in the jet further away from the steam inlet. Jet centerlines of velocity and temperature are measured and positions are compared. Different locations for J\100 and low TL are explained from dependencies on Reynolds and Prandtl numbers. Next to the jet centerline a second high-temperature zone was found to occur, close to the wall and downstream of the steam inlet. The importance of capillary forces is investigated with the aid of 3D CFD computations.