Mass-weighted dust temperature (〈T_d〉, top row), dust column density (N_d, middle row), and FIR intensity (I_FIR, bottom row) along the y-axis of a portion of MC2-HD centred around bubble 2 (see Table 3) at t_evol = 2–4 Myr (from left to right). The expansion of the bubble progressively enlarges the region with warm dust, characterised by 〈T_d〉 ≳ 20 K. However, Nd in the warm region is reduced by the expansion of the bubble, which pushes the dust into the much cooler shell of the bubble. As a consequence, I_FIR arises from a progressively larger, but less FIR-bright area. This is also reflected in the total L_FIR, reported for each snapshot in the I_FIR maps.