A constitutive relationship is developed to characterize the flow of high velocity, compressible, heated gases through concrete. This relationship equates a nondimensional flow parameter with pressure and temperature ratios across the medium. The key premise is that the resistance to flow through a porous medium can be modeled with friction coefficients analogous to the method used for simpler geometries. The utility of a porous media compressible flow parameter is appraised by comparing it with the Forchheimer equation modified for an ideal gas. There is little difference in adiabatic flow rates predicted by the two relationships. The Forchheimer equation does not account for the effects of heating. The flow parameter predicts mass flows through a slab of concrete to decrease by nearly 50% when this medium is heated from 25 to 350oC.