PEMFCs, vital for clean energy tech, face issues with excess heat production affecting durability. Cooling systems are crucial to maintain safe temperatures, with liquid cooling more effective than air cooling. Hybrid nanofluids, combining nanoparticles in base fluids like water or EG, show promise for improved thermal characteristics. Studies investigate optimal base fluid ratios for enhanced thermal conductivity, with research highlighting the benefits of incorporating rGO in hybrid nanofluids. Promising results show that rGO enhances thermal conductivity, improving heat transfer efficiency in PEMFCs. Researchers emphasize the need for further exploration of smart nanofluids for scalable and efficient cooling solutions in PEMFCs to enhance performance and durability.