  We consider a Schwarzschild-de Sitter (SdS) black hole, and focus on the
emission of massless scalar fields either minimally or non-minimally coupled to
gravity. We use six different temperatures, two black-hole and four effective
ones for the SdS spacetime, as the question of the proper temperature for such
a background is still debated in the literature. We study their profiles under
the variation of the cosmological constant, and derive the corresponding
Hawking radiation spectra. We demonstrate that only few of these temperatures
may support significant emission of radiation. We finally compute the total
emissivities for each temperature, and show that the non-minimal coupling
constant of the scalar field to gravity also affects the relative magnitudes of
the energy emission rates.
