Temperature at A_V = 20 without mechanical heating. Higher equilibrium temperatures are attained for dense molecular clouds (top right corner) with decreasing equilibrium temperature towards low n and G₀. Below the 20 K contour, all temperatures are set to 10 K – the minimum allowed in the code. The red dashed lines mark the densities n = n_c where Γ_mech = Γ_{total,surface} from Table 2.