Radiation heat transfer in a planar participating medium which scatters anisotropically is scaled to an isotropically scattering medium. Only isotropic scattering problems need to be solved with a scaled optical depth and albedo. The scaling is derived from approximate solution methods to the equation of transfer. From the P-1 approximation, the two-flux method, and the modified linear anisotropic scattering model, three scalings are derived. The scaling that gives the best results when comparing the scaled solutions to exact solutions is the one derived from the P-1 approximation.