Run of the ratio θ ≡ T/T_F as a function of the mass (in solar units) enclosed within a distance r from the centre, for the He-core at three different stages of the RGB evolution of a model with the labelled total mass, initial helium mass fraction Y and a metal mass fraction Z (metal distribution α-enhanced, with [α/Fe] = 0.4, typical of Galactic halo stars) corresponding to [Fe/H] = −1.5. The discontinuity at M_r ≈ 0.2 M_⊙ in the structure corresponding to the TRGB stellar model is due to off-center He-burning ignition that starts removing the electron degeneracy.