  Starting from a microcanonical statistical approach and special relativity,
the relativistic transformations for temperature and pressure for an ideal gas
of bradyons, luxons or tachyons is found. These transformations are in
agreement with the three laws of thermodynamic and our temperature
transformation is the same as Ott's. Besides, it is shown that the
thermodynamic $dS$ element is Lorentz-invariant.
