inferred from [MagPhys]{} modelling [@daCunha2015]. The more precise spectroscopic redshifts and additional ALMA photometry result in a temperature increase compared to values reported by @daCunha2015 $T_\mathrm{dust}=46^{+0}_{-3}$ K and $43^{+15}_{-14}$ K, respectively. Elevated $T_\mathrm{dust}$ in intensely star-forming $z\sim4.5$ galaxies was reported by @Cooke2018, who interpret the inferred median $T_\mathrm{dust}=55\pm4$ K as evidence for high $\Sigma_\mathrm{SFR}$ at high redshift. Note that the @daCunha2015 and @Cooke2018 models use *Herschel* SPIRE and ALMA Band 7 photometry, while our models include ALMA Bands 3, 4 and 8 observations, thus better sampling the Rayleigh-Jeans tail of dust thermal spectrum. Compared to the [MagPhys]{} models of the entire ALESS sample [@daCunha2015], ALESS 49.1 and 57.1 have SFR higher by a factor of $\sim$2 (@daCunha2015: median SFR = 280$\pm$70 M$_\odot$ yr$^{-1}$) and stellar mass factor of 2 lower (@daCunha2015: $M_* = (8.9\pm0.1)\times10^{10}$ M$_\odot$ yr$^{-1}$); the dust mass is consistent with the median @daCunha2015 value ($(5.6\pm1.0)\times10^{10}$ M$_\odot$). The gas depletion timescale $M_\mathrm{gas}$/SFR is 100$\pm$40 Myr in both ALESS 49.1 and 57.1, in line with $z\simeq2-4$ SMGs [@Huynh2017; @Bothwell2013], and a few times lower than claimed for $z=1-3$ massive main-sequence galaxies from the PHIBBS survey ($0.7\pm0.1$ Myr, @Tacconi2018).

Using the SED models, we can estimate the fraction of the 160-$\mu$m 