  We point out how to construct the Hartle-Hawking-Israel state for the
minimaly coupled massless quantum real scalar field in the two dimensional BTZ
black hole. We also calculate the renormalized energy-momentum tensor for the
same field in the eternal CGHS black hole, AdS, Robertson-Walker and Rindler
spacetime in two dimensions. We also discuss the Boulware, the
Hartle-Hawking-Israel and the Unruh state for the eternal CGHS black hole.
