CO(2–1)/CO(1–0) measured on 140 pc scale at the positions of clouds in NGC 628. As in Fig. 3, the headlight cloud is the red point, and the nine next most luminous molecular clouds (M_lum >  8.6 × 10⁶ M_⊙) are in blue. The kiloparsec scale estimate for CO(2–1)/CO(1–0) in NGC 628 measured by EMPIRE is indicated with a dashed black line, and the average value for the cloud-scale measurements is represented by a dashed gray line. The CO(2–1)/CO(1–0) measurements in this plot use the peak brightness of the CO(1−0) and CO(2−1) lines within a box centered on the cloud position.