Hot dust temperature T_single derived from the single-epoch decomposition, where T is a free parameter in each epoch, versus the temperature T_multi from the multiepoch fits, in which T evolves according to Eq. (4) and only the initial temperature T₀ is a free parameter. For epochs 1–9, the temperature resulting from the epoch 1–9 fit is plotted, for epochs 10–29 the temperature from the epoch 7–29 fit. The minimum that is seen in T_single around MJD 56 700 (and also in the corresponding JHK flux minima) is not covered within the sampling of the z-band data (see Figs. 8 and 2), therefore we observe a substantial discrepancy between T_single and T_multi around that date.