  We propose a modified version of the Horowitz-Maldacena final-state boundary
condition based upon a matter-radiation thermalization hypothesis on the Black
Hole interior, which translates into a particular entangled state with thermal
Schmidt coefficients. We investigate the consequences of this proposal for
matter entering the horizon, as described by a Canonical density matrix
characterized by the matter temperature $T$. The emitted radiation is
explicitly calculated and is shown to follow a thermal spectrum with an
effective temperature $T_{eff}$. We analyse the evaporation process in the
quasi-static approximation, highlighting important differences in the late
stages with respect to the usual semiclassical evolution, and calculate the
fidelity of the emitted Hawking radiation relative to the infalling matter.
