  We study the properties of black-holes (BHs) that are out of equilibrium
about the Hartle-Hawking (HH) vacuum state. We show how gravitational
perturbations excite the vacuum state, thus making it a superposition of
states, which eventually leads to additional excitations. We examine the vacuum
state structure in the presence of time-dependent gravitational perturbation.
As a result, we determine the vacuum state evolution and calculate the
semi-classical modifications to the particle occupation number of the emitted
particles. We demonstrate that the quantum emission in BHs that are far away
from equilibrium is comparable and even larger than the Hawking radiation.
