  The temperature at the end of reheating and the length of this cosmological
phase can be bound to the inflationary observables if one considers the
cosmological evolution from the time of Hubble crossing until today. There are
many examples in the literature where it is made for single-field inflationary
models and a constant equation of state during reheating. We adopt two simple
varying equation of state parameters during reheating, combine the allowed
range of the reheating parameters with the observational limits of the scalar
perturbations spectral index and compare the constraints of some inflationary
models with the case of a constant equation of state parameter during
reheating.
