Near-extremal black holes
  We present a new formulation of deriving Hawking temperature for near-extremal black holes using distributions. In this paper the near-extremal Reissner-Nordstrom and Kerr black holes are discussed. It is shown that the extremal solution as a limit of non-extremal metric is well-defined. The pure extremal case is also discussed separately. 
Bhramar Chatterjee and Amit Ghosh
gr-qc hep-th