Evolution of cooling and heating components of the gas temperature in a 10⁸ M_⊙ collapsing cloud as a function of time, normalized by t_coll. All the components are described in terms of energy density per second. Ψ_grav arises from to gravitational collapse of the gas; Ψ_com is due to Compton coupling. Finally, ${\mathrm{\Psi }}_{\mathrm{mol}}={\mathrm{\Psi }}_{{\mathrm{H}}_2}+{\mathrm{\Psi }}_{\mathrm{HD}}$ corresponds to the thermal contribution of molecules H₂ and HD. The negative components Ψ_com, Ψ_mol, ${\mathrm{\Psi }}_{{\mathrm{H}}_2}$, and Ψ_HD are displayed as absolute values.