  We argue that extensions of the SM with a warped extra dimension, together
with a new $\mathbb{Z}_2$-odd scalar singlet, provide a natural explanation not
only for the hierarchy problem but also for the nature of fermion bulk masses
and the observed dark matter relic abundance. In particular, the Kaluza-Klein
excitations of the new scalar particle, which is required to naturally obtain
fermion bulk masses through Yukawa-like interactions, can be the leading portal
to any fermion propagating into the bulk of the extra dimension and playing the
role of dark matter. Moreover, such scalar excitations will necessarily mix
with the Higgs boson, leading to modifications of the Higgs couplings and
branching ratios, and allowing the Higgs to mediate the coannihilation of the
fermionic dark matter. We study these effects and explore the viability of
fermionic dark matter in the presence of these new heavy scalar mediators both
in the usual freeze-out scenario and in the case where the freeze-out happens
during an early period of matter domination.
