  In this paper we study the dissipative effects and decoherence induced on a
particle moving at constant speed in front of a dielectric plate in quantum
vacuum, developing a Closed-Time-Path (CTP) integral formulation in order to
account for the corrections to these phenomena generated by finite
temperatures. We compute the frictional force of the moving particle and find
that it contains two different contributions: a pure quantum term due to
quantum fluctuations (even present at vanishing temperatures) and a temperature
dependent component generated by thermal fluctuations (bigger contribution the
higher the temperature). We further estimate the decoherence timescale for the
internal degree of freedom of the quantum particle. As expected, decoherence
time is reduced by temperature, however, this feature is stronger for large
velocities and for resonant situations. When the particle approaches
relativistic speed, decoherence time becomes independent of temperature. The
finite temperatures corrections to the force or even in the decoherence
timescale could be used to track traces of quantum friction through the study
of the velocity dependence since the solely evidence of this dependence
provides an indirect testimony of the existence of a quantum frictional force
