Forced convection in a parallel plate channel filled with a porous medium, consisting of two layers with the same porosity and permeability but with different solid conductivity, and saturated by a single fluid, is analyzed using a two-temperature model. It is found that the effect of local thermal nonequilibrium is particularly significant when the solid conductivity in each layer is greater than the fluid conductivity, and in these circumstances the effect is to reduce the Nusselt number defined in terms of the overall effective thermal conductivity.