  We study the fluctuation-electromagnetic interaction and dynamics of a small
spinning polarizable particle moving with a relativistic velocity in a vacuum
background of arbitrary temperature. Using the standard formalism of the
fluctuation electromagnetic theory, a complete set of equations describing the
decelerating tangential force, the components of the torque and the intensity
of nonthermal and thermal radiation is obtained along with equations describing
the dynamics of translational and rotational motion, and the kinetics of
heating. An interplay between various parameters is discussed. Numerical
estimations for conducting particles were carried out using MATHCAD code. In
the case of zero temperature of a particle and background radiation, the
intensity of radiation is independent of the linear velocity, the angular
velocity orientation and the linear velocity value are independent of time. In
the case of a finite background radiation temperature, the angular velocity
vector tends to be oriented perpendicularly to the linear velocity vector. The
particle temperature relaxes to a quasistationary value depending on the
background radiation temperature, the linear and angular velocities, whereas
the intensity of radiation depends on the background radiation temperature, the
angular and linear velocities. The time of thermal relaxation is much less than
the time of angular deceleration, while the latter time is much less than the
time of linear deceleration.
