Water-spray cooling of heated surfaces is common ill many industrial applications, notably steelmaking, because of its high heat dissipating ability. Quantitative information regarding the parameters affecting spray cooling is relatively scarce. The objective of this research is to obtain such information by using a specially developed experimental technique that provides steady-state cooling of a steel surface losing a gas-fired burner to introduce heat. The method provides fundamental information oil the spray parameters controlling heat transfer from horizontal heated surfaces for a wide range of mass flux and droplet size and velocity ill the film-boiling regime. Measurements are made of the drop sizes and velocities and of the liquid mass flux ill the sprays produced by full-cone pressure atomizers. Heat transfer characteristics it? the range of surface temperature between 380 K and 1200 K are investigated. Comparisons are made with published data and correlations are developed for heat flux and Nusselt number ill the surface temperature range from 800 to 1200 K. It is found that drop size has only a weak effect oil heat transfer ill these relatively dense sprays. However, droplet velocity is almost as important as mass flux, so that the product of mass flux and velocity, the impinging momentum flux of water, is the dominant parameter.