Opacities of H₂O (blue) and HDO (orange) at T = 300 K (upper panel), T = 700 K (middle panel) and T = 1100 K (lower panel), at P = 10⁻² bar, which is a representative pressure value probed by water and HDO in the calculations considered here. The opacities have been scaled such that H₂O constitutes 99.7% and HDO 4 × 10⁻⁵ of all H₂O molecules. The higher the temperature, the more shielding of HDO occurs by H₂O.