I_[CII]/I_FIR as a function of the distance d from the main star of all HII regions found in the investigated clouds. At small d, I_[CII]/I_FIR drops to 10⁻⁶ − 10⁻⁴, depending on the regions and snapshots. At larger radii, the ratio is ~10⁻² at early stages, and ~10⁻³ at later stages. The drop of the ratio at later stages is mostly due to the overall dust heating in the entire cloud caused by the various stars which have already formed.