  We investigate the conditional average and the conditional variance of
dissipated energy considering, as a prototypical example, a driven spin-boson
system. We follow a measurement protocol in which the spin is prepared in a
certain initial state before undergoing a periodic driving. Subsequently, the
spin is projected onto a post-selected final state. We compare the conditional
average of dissipated energy to the lower bound which directly follows from the
well known fluctuation relations. We further report that a special selection of
the initial (pre-selected) and final (post-selected) spin states leads to an
enhanced energy emission with simultaneous noise suppression at driving times
of order of the relaxation time.
