Comparison of cooling functions Λ(T) for different chemical abundances. The thin and thick lines show the radiative cooling for Solar and three times Solar abundances, respectively. The dashed blue, dotted orange, and dot-dashed green lines represent the cooling functions for atmosphere abundances corresponding to WR subtypes: WC8-9, WN5-7, WN8-9 and Ofpe/WN9 based on the compositions compiled shown in Table 1. The contributions of each element to the radiative cooling were taken from the plasma models by Štofanová et al. (2021). Additionally, the cooling function used in Ressler et al. (2018) is shown as a thick black line.