Example spectra of thermometer lines CH₃CN J = 13-12, CH₃CCH J = 14-13, H₂CS J = 6-5, H₂CS J = 7-6 at the continuum peak of the target source. The blue profiles show the XCLASS LTE fitting results. For source G31.412+0.307, which presents significant line blending from other species, the fittings also included those species and transitions that can potentially make prominent contributions to the spectrum.