  We study the consequences of reheating in quintessential inflation. From
simple inflationary quintessential models introduced in cite{hap, hap2}, we
show that when the reheating is due to the production of heavy massive
particles conformally coupled with gravity, a viable model which matches with
the current observational data cite{Ade, Planck, bicep2} is only possible for
reheating temperatures that range between $1$ GeV and $10^4$ GeV. On the other
hand, when the universe reheats via the production of massless particles, the
viability of the model is only possible when those particles are nearly
conformally coupled with gravity, leading to a reheating temperature between
$1$ MeV and $10^4$ GeV.
