The behaviour of gases at moderately high temperatures of the order of 10$^4$ K, undergoing inelastic collisions and affected by radiation is studied in this paper by means of a modified Boltzmann equation. In the calculations, suitable inelastic collision cross-sections agreeing well with experimental results for argon are used. The non-Maxwellian distribution arising out of these processes is obtained and, following the Chapman-Enskog-Hilbert procedure, the non-uniform state of such a gas is studied. The behaviour of viscosity, thermal conductivity and diffusivity is analysed. Finally, this analysis is applied to a one-dimensional normal shock. It is found that these inelastic processes considerably thicken the shock and, though there is only a weak 'precursor' effect, the tail behind the shock is extended. The density and temperature profiles are obtained.