  The Unruh vacuum not admitting any outgoing flux at the horizon implies that
the origin of the outgoing Hawking radiation is the atmosphere of a
near-horizon quantum region without resort to the firewall; however, the
existence of the firewall of superplanckian excitations at the horizon can be
supported by the infinite Tolman temperature at the horizon. In an exactly
soluble model, we explicitly show that the firewall necessarily emerges out of
the Unruh vacuum so that the Tolman temperature in the Unruh vacuum is
divergent in essence due to the infinitely blueshifted negative ingoing flux
crossing the horizon rather than the outgoing flux. We also show that the
outgoing Hawking radiation in the Unruh vacuum indeed originates from the
atmosphere, not just at the horizon, which is of no relevance to the infinite
blueshift. Consequently, the firewall from the infinite Tolman temperature and
the Hawking radiation from the atmosphere turn out to be compatible, once we
waive the claim that the Hawking radiation in the Unruh vacuum originates from
the infinitely blueshifted outgoing excitations at the horizon.
