Original (left) and combined (center column) dust temperature images and their subtraction (right) for the Young protocluster W43-MM1 (upper) and the Evolved protoclusters G012.80 (central row) and W51-IRS2 (lower). In the right panels, bright areas represent gas structures, whose 70 μm flux is extinguished by the protocluster high column density gas. Their temperature has been increased by the opacity-corrected procedure of PPMAP. Unresolved bright and dark sources are the luminous protostellar cores and, low-luminosity protostellar or prestellar cores, respectively. White circles mark the areas heated beyond the 2.5″ beam of PPMAP by the brightest protostars of these regions.