  This note is an Addendum to our previous article [Phys. Rev. A \textbf{81},
053820 (2010)]. We show that under the assumption of a Bose-Einstein
distribution for the thermal reservoir, zero-temperature properties of the
entangled states considered there are not changed by heating, for temperatures
up to the order of room temperatures. In this case, the system is dissipative
in free space and presents stability for a small cavity, both for T=0 and for
finite temperature.
