The paper presents experimental and numerical investigations on subsonic turbulent wall flows on strongly heated or cooled flat plates. Based on experimental results obtained for flow temperatures between minus 60 degree C and plus 350 degree C, wall temperatures of 10 degree C to 50 degree C at free stream velocities between 9 m/s and 23 m/s, the boundary layer laws of velocity and temperature are discussed as well as the resulting heat transfer laws.