  I present exact results matching Kerr-Newman Black Hole thermodynamics in the
extremal limit to the two-dimensional Fermi Gas. Two dimensions are consistent
with the membrane paradigm of black holes. Key in the analysis is the
thermodynamic Riemannian curvature scalar $R$, negative for most ordinary
thermodynamic systems, including those near the critical point, but mostly
positive for the Kerr-Newman Black Hole and the Fermi Gas.
