  We compute Schwinger pair production rates at finite temperature, in the
presence of homogeneous, concurrent electric and magnetic fields. Expressions
are obtained using the semiclassical worldline instanton formalism, to leading
order, for spin-$0$ and spin-$\frac{1}{2}$ particles. The derived results are
valid for weak coupling and fields. We thereby extend previous seminal results
in the literature, to coexistent electric and magnetic fields, and fermions.

High Energy Physics - Theory;High Energy Astrophysical Phenomena;High Energy Physics - Experiment;High Energy Physics - Phenomenology