A system and method for maintaining a temperature of a power system using a cooling system that includes an impeller and a phase change material. During normal operation of the cooling system, heat that is generated by the operation of an electronic device(s) of the power system can be transferred primarily by conduction through an upper base plate and fins of a heat sink, and dissipated via forced convection that is generated by the impeller. Additionally, the phase change material is positioned outside of a main heat flux path of the heat sink such that, during normal operation of the cooling system, the phase change material does not provide a heat flux obstruction. In the event of an impeller failure, the phase change material provides at least a temporary cooling source for an extended period of time via the relatively large latent heat capacity of the phase change material.