Assumed gas density (top) and computed gas and dust temperature (middle and bottom panels) in the DALI model for a typical disk around a Herbig Ae star with a luminosity of 36 L_⊙. Only the region where n(gas) > 10⁶ cm^-3 is shown. The position of the star is indicated with the symbol of a black star and the T_dust = 150 K line, approximating the water snow surface, is indicated with the solid grey line.