Distribution of the rotational temperatures, overlaid on the 8 μm image of Spitzer. The values derived from hyperfine fitting of the (1, 1) line are labelled in blue; those derived from Gaussian fitting of both lines are shown in yellow; red labels correspond to the positions with the highest values of T_rot (see text). In all cases, fitting of the (2, 2) has been obtained with a single Gaussian component. The low temperatures associated with the IRDC, and higher values elsewhere are clearly revealed.