  We present a classical approach of a mixture of compressible fluids when each
constituent has its own temperature. The introduction of an average temperature
together with the entropy principle dictates the classical Fick law for
diffusion and also novel constitutive equations associated with the difference
of temperatures between the components. The constitutive equations fit with
results recently obtained through Maxwellian iteration procedure in extended
thermodynamics theory of multitemperature mixtures. The differences of
temperatures between the constituents imply the existence of a new dynamical
pressure even if the fluids have a zero bulk viscosity. The nonequilibrium
dynamical pressure can be measured and may be convenient in several physical
situations as for example in cosmological circumstances where - as many authors
assert - a dynamical pressure played a major role in the evolution of the early
universe.
