  The behavior of $\eta$ and $\eta'$ in hot strange quark matter in weak
equilibrium with temperature, is investigated within the SU(3)
Nambu-Jona-Lasinio [NJL] model. Possible manifestations of restoration of
symmetries, by temperature or density, in the behavior of $\eta$ and $\eta'$
are discussed. The role played by the combined effect of temperature and
density in the nature of the phase transition and meson behavior is also
analyzed.
