He II/He I luminosity ratio against T_BB. The ratio reaches values smaller than one for those TDEs that have low temperatures. In addition, TDEs AT2018zr and LSQ12dyw, which have the lowest T_BB in our sample, do not show He II, only He I hence we place upper-limits for those. An indication that probably He (in the line emitting region) is not yet ionized for such photospheric temperatures (≤20 000 K).