Fiber optic sensors are embedded in transformer windings for real-time hot spot temperature monitoring. DTS systems monitor the thermal profile of downhole environments over thousands of meters. Fiber optic temperature sensors are advanced IoT devices that utilize optical fibers, which are thin strands of glass or plastic. With the fundamental properties of light, such as intensity, polarization, and wavelength, these. Fiber optic temperature sensors are immune to the many environmental effects that compromise other measurement technologies, can be embedded and installed in locations traditional temperature sensors cannot and deliver an unprecedented level of spatial detail and data without sacrificing precision. Traditional point sensors provide temperature data at a single location,limiting the ability to capture a complete picture of thermal distribution. FOSS technology offers a groundbreaking alternative for temperature. Fiber optic temperature sensors offer superior performance compared to these techniques, thanks to their numerous benefits., thermocouples, RTDs), fiber optic sensors offer significant advantages such as immunity to electromagnetic interference. These features of optical fibers make them a useful tool for various sensing applications including in medicine, automotives, biotechnology, food quality control, aerospace, physical and chemical monitoring.