Noble metal nanoparticles with homogeneity in size, shape, and surface properties have potential applications for bioimaging, biomedical diagnosis, and therapy. Gold nanoparticles being the most efficient among all other known noble metal nano particles. Here we illuminate that due to plasmonic resonance, a metal nanoparticle features enhanced light absorption, turning it into an ideal nano-source of heat. Hence forming basis of thermo plasmonics. The recent progress of this emerging and fast-growing field is reviewed and some of its most recent applications based on the heat generated by gold nanoparticles are discussed, namely photothermal cancer therapy, nano surgery, drug delivery, photothermal imaging, protein denaturation, photoacoustic imaging, nano-chemistry, heat-assisted magnetic recording and single living cell experiments.