Most research work about thermal spraying involves the special process itself, the spray powder materials and the coatings. The major aim is to clarify the basic relations between different spray parameters and the coating properties, such as bond strength, porosity, wear resistance and residual stress. This paper presents temperature measurements of the substrate while a spray stream is directed at the surface. The substrate temperature was measured with an infrared camera at the back side of a sample. The camera allows a measuring frequency of 4 Hz using 140 by 140 pixel view field. Basic studies were carried out with a High Velocity Oxygen Fuel (HVOF)- System. Typical HVOF parameters were compared while spraying different tungsten carbide alloys on aluminum substrates. Comparative studies with plasma processes were performed. These results should help to calculate the temperature and thermal expansion of real parts with various structures before the spray process is used to apply a coating.