  We study a periodically driven (symmetric as well as asymmetric)double-well
potential system at finite temperature. We show that mean heat loss by the
system to the environment(bath) per period of the applied field is a good
quantifier of stochastic resonance. It is found that the heat fluctuations over
a single period are always larger than the work fluctuations. The observed
distributions of work and heat exhibit pronounced asymmetry near resonance. The
heat losses over a large number of periods satisfies the conventional
steady-state fluctuation theorem, though different relation exists for this
quantity.
