Illustration of the effects of differences in the physics input on the long-term evolution of a neutron star. Redshifted thermal luminosity is shown as a function of time. Dotted line (1) – Basic cooling model. Solid line (2) – Same model with heating according to the FZCPHG model, calculated assuming that the accretion starts shortly after the birth of the neutron star with constant average rate of 10⁻¹⁰ M_⊙ yr⁻¹. Dot-dashed line (3) – Same with replacement of the iron heat-insulating envelope to an accreted He/C envelope. Long-dashed line (4) – Same accreted envelope, but the alternative heating model. Short-dashed line (5) – Same but without baryon superfluidity in the core.