  In semiclassical gravity, the vacuum expectation value
${\langle\hat{N}\rangle}$ of the particle number operator for a quantum field
gives rise to the perception of thermal radiation in the vicinity of a black
hole. This Hawking effect has been examined only for observers asymptotically
far from a Kerr black hole; here we generalize the analysis to various classes
of freely falling observers both outside and inside the Kerr event horizon. Of
note, we find that the effective temperature of the ${\langle\hat{N}\rangle}$
distribution remains regular for observers at the event horizon but becomes
negative and divergent for observers reaching the inner Cauchy horizon.
Furthermore, the perception of Hawking radiation varies greatly for different
classes of observers, though the spectrum is generally a graybody that
decreases in intensity with black hole spin and increases in temperature when
looking toward the edges of the black hole shadow.
