  Relativistic heat transport in electron-two-temperature plasmas with density
gradients has been investigated. The Legendre expansion analysis of
relativistically modified kinetic equations shows that strong inhibition of
heat flux appears in relativistic temperature regimes, suppressing the
classical Spitzer-H{\"a}rm conduction. The Seebeck coefficient, the
Wiedemann-Franz law, and the thermoelectric figure of merit are derived in the
relativistic regimes.
