p - H₂CO-measured temperature against the predicted turbulent-driven temperature as discussed in Sect. 5.1. While no trend is obvious in the data, most of the high signal-to-noise data points are fairly close to the T_G,turb = T_G,measured line. There are few points with T_G,measured>T_G,turb, so turbulence generally provides enough – and sometimes too much – energy to heat the gas to the observed temperatures. The regions with predicted temperatures higher than observed require additional explanation: either their heating rate has been overestimated or their cooling rate underestimated. a) The hand-selected regions as described in Fig. 12; the blue symbols are compact “clump” sources and the red symbols are large-area square regions. Triangles indicate regions with lower limits on the measured temperature, i.e. any region with a measured 1−σ lower limit on the temperature T_G> 150 K. The gray dashed line shows the T_G,turb = T_G,measured relation. Regions that are inconsistent with the relation at the 1−σ level are outlined. b) The same as a) for the dendrogram-extracted regions. Regions with a large Gaussian correction factor f_g> 3 are excluded. Regions with T_G,turb> 180 K are indicated with triangles. The points are color coded by signal-to-noise in the ratio R₁, with gray S/N< 5, blue 5 <S/N< 25, green 25 <S/N< 50, and red S/N> 50. If the lower signal-to-noise points in blue and gray are ignored, the agreement between the predicted temperature and observed temperature is fairly good.