  A semiclassical approach that incorporates quantum mechanical behavior of
heat capacity in direct caloric effect simulations is proposed. Application of
this methodology to study electrocaloric effect in prototypical ferroelectrics
${ \rm PbTiO_3 }$, and ${ \rm BaTiO_3 }$, reveals severe underestimation of
electrocaloric response at lowest temperatures by classical simulations. The
discrepancy between semiclassical and classical results are found to be largest
in ferroics with Debye temperature exceeding the Curie point. A route to
enhance electrocaloric effect by tuning the Debye temperature in composite
materials is proposed.
