  In this paper, we demonstrate that the hybrid normal-superconducting-normal
(NSN) structure has potential for a multifunctional thermal device which could
serve for heat flux control and cooling of microstructures. By adopting the
scattering matrix approach, we theoretically investigate thermal and electrical
effects emerging in such structures due to the Cooper pair splitting (CPS) and
elastic cotunneling phenomena. We show that a finite superconductor can, in
principle, mediate heat flow between normal leads, and we further clarify
special cases when this seems contradictory to the second law of
thermodynamics. Among other things, we demonstrate that the CPS phenomenon can
appear even in the simple case of a ballistic NSN structure.
