Hawking Radiation Entropy and Horizon Divergences

We review the problem of divergences in one--loop thermodynamical quantities for matter fields in thermal equilibrium on a black hole background. We discuss a number of results obtained for various thermodynamical quantities. Then we discuss the ansatz called ``literal interpretation" of zeroth law of black hole mechanics and try to explain the diseases of the conical defect procedure in light of this ansatz. Finally, an analysis of the consequences implied by our ansatz on the calculation of the partition function is made.