It is shown that, at low temperature and high polarization, a spin-1/2 Fermi system becomes a mixture of a degenerate fluid (up spins) and a fluid described by Boltzmann statistics (down spins). The down spins become classical when the polarization is so high that their Fermi energy becomes much less thankT. For weakly interacting systems the coefficients of thermal conductivity, viscosity, and spin diffusion are computed by kinetic theory arguments and from the Boltzmann equation. Comparisons are made with coefficients of the fully degenerate systems at zero and high polarization; altered temperature and magnetic field dependences result.