  There exist several well-established procedures for computing thermodynamics
for a single horizon spacetime. However, for a spacetime with multi-horizon,
the thermodynamics is not very clear. It is not fully understood whether there
exists a global temperature for the multi-horizon spacetime or not. Here we
show that a global temperature can exist for Schwarzschild-de Sitter spacetime,
Reissner-Nordstrom-de Sitter spacetime, and rotating BTZ black hole. This
temperature does not coincide with the conventional Hawking temperature related
to the outer horizon. We also show that the total entropy for these spacetimes
can not be determined only by the outer horizon. The correlations between the
horizons of these spacetimes determine it.
