  We demonstrate the importance of near-infrared radiation from hot dust for
Compton cooling of electrons/positrons in quasar jets. In our model, we assume
that the non-thermal radiation spectra observed in OVV quasars are produced by
relativistic electrons/positrons accelerated in thin shells which propagate
down the jet with relativistic speeds. We show that the Comptonization of the
near-IR flux is likely to dominate the radiative output of OVV quasars in the
energy range from tens of keV up to hundreds of MeV, where it exceeds that
produced by Comptonization of the UV radiation reprocessed and rescattered in
the Broad Emission Line region. The main reason for this lies in the fact that
the jet encounters the ambient IR radiation over a relatively large distance as
compared to the distance where the energy density of the broad emission line
light peaks. In the soft - to mid energy X-ray band, the spectral component
resulting from Comptonization of the near-IR radiation joins smoothly with the
synchrotron-self-Compton component, which may be responsible for the soft X-ray
flux. At the highest observed gamma-ray energies, in the GeV range,
Comptonization of broad emission lines dominates over other components.
