Comparison between the net-proton normalized second-order cumulant as a function of the average multiplicity at midrapidity measured by the ALICE Collaboration in Pb--Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV (blue circles)  and the predictions of the Thermal-FIST model, with $T_{\mathrm{chem}}=155$ MeV and $V_{\mathrm{c}}=3\ \mathrm{d}V/\mathrm{dy}$ (orange band).