In this presentation, we introduce a nanoscale heating source (“nanoheater”) based on an exothermic reaction between aluminum (Al) and nickel (Ni). The formation process of Al and Ni alloys is a good candidate for heat-generation purposes due to its large exothermic reaction enthalpies. The fabrication and characterization of various types of nanoheater structures, e.g., bi-metallic nanowires and core-shell nanoparticles, will be presented. These Ni-Al hetero- nanostructures are synthesized by either chemical or physical methods, and are characterized with SEM and TEM. Upon ignition using different methods such as electrical, magnetic field, or infrared heating, Ni-Al alloys are formed and one-time controlled and localized heat is generated from the exothermic reaction process. The potential applications of these nanoheaters in nanomaterial processing and biomedical field will also be discussed.