Heating rate compared with A_V, or depth into cloud. The total heating is shown in black, the cosmic ray heating in purple, the mechanical heating in blue, and the photoelectric heating in orange. The top row is for case 1 with one mPDR, one CDR, and one mCDR. The middle row is case 2 with two mPDRs and one mCDR and the bottom row is case 3 with three mPDRs. The first column is for the first component in each case, the mPDR, and it is the same in all three cases. The second and third columns represent the second and third ISM phases for each case. The vertical dotted line in these plots represents the edge of the PDR, as some of the models we use have A_V< 5. Finally, the last column is the integrated heating rates for all ISM phases.