Controlling and mitigating hot-spot formations in energetic materials, e.g. polymer-bonded explosive (PBXs), is vital to improving their overall safety. Here we study the effect of incorporating nano-inclusions, e.g. multi-walled carbon nanotubes and silver nano-particles, into the polymer binder of an inert PBX simulant (PBS). The thermomechanical behavior of these nano-PBS materials is characterized via thermal diffusivity measurements, quasi-static compression testing to failure, and low-speed drop-weight impact testing. The nano-inclusions are shown to increase the bulk thermal diffusivity of these composite materials. This is particularly important as the enhanced diffusivity may help to conduct heat away from a hot-spot as it begins to form, thereby potentially avoiding an unintended detonation. This hypothesis is further studied through low-speed drop-weight impact testing coupled with moderately high-speed thermography. In these experiments, the energetic materials without nano-inclusions are observed to exhibit higher temperature hot-spots than a nano-inclusion enhanced energetic materials when subject to similar conditions. These results demonstrate the role that nano-inclusions can play in weakening hot-spot formation in energetic materials. Further supporting evidence is provided by a set of finite element calculations, which clearly show the role of thermal conductivity in hot-spot formation.