The chapter elucidates some of the significant work done on the use of flexible pyroelectric sensing prototypes for energy-harvesting applications. The efficiency of these sensors has been judged based on the diversified temperature variant shown with respect to the disparate materials processed to form the sensors. These sensing prototypes have been used in pure and combined forms, where other major forms like piezoelectric and triboelectric sensors have been conjugated with them for a wide range of applications. Some of the pyroelectric polymers like PVDF have been combined with carbon-based allotropes and metallic nanowires to develop highly efficient prototypes. A few of the major research work related to the deployment of these sensors for temperature sensing and other types of biomedical uses have been highlighted. Finally, some of the existing challenges, along with the probable solutions, have been mentioned in the chapter.