The relativistic transformation equations for the pressure, volume, energy, and momentum of a gas in a closed container are discussed. Considerations are given in support of pressure noninvariance, volume dilatation, and the fact that the energy and momentum of a gas form a four-vector. It is shown that the relativistic transformation formula for temperature resulting from the Lorentz invariance requirement of the equation of state of an ideal gas coincides with the Ott formula.