Dust temperature map derived from emission distributions at 60 and 100 μm. The cyan (+) and blue (x) symbols mark the position of the H II regions from the WISE and Sharpless catalogues, respectively. These represent a subsample of the catalogued H II regions, whose selection criteria are described in Sect. 4. Contours are at 25 and 27 K. Coloured ellipses mark the locations of the four H I shells.