Abstract
In this work, we consider a two level Pσ_z pseudo-Hermitian system in contact with a thermal bath to study various thermodynamic properties. The system is realized in terms of infinitely many invariant subspaces. We find explicit solution in each subspace analytically. The quantum system undergoes a Pσ_z phase transition in each invariant subspace, when the non-Hermitian coupling exceeds a certain critical value (μ_c). We calculate various thermodynamic quantities and observe that these quantities show divergences exactly at the exceptional points (EPs) of the theory.