  We study the decay of a near-extremal black hole in AdS$_2$, related to the
near-horizon region of 3+1-dimensional Reissner-Nordstr\"om spacetime,
following Fabbri, Navarro, and Navarro-Salas. Back-reaction is included in a
semiclassical approximation. Calculations of the stress-energy tensor of matter
coupled to the physical spacetime for an affine null observer demonstrate that
the black hole evaporation proceeds smoothly and the near-extremal black hole
evolves back to an extremal ground state, until this approximation breaks down.
