Two-phase immersion cooling has emerged as a promising solution for efficient and effective thermal management in high-performance computing applications. This study presents the results of detailed experimental investigations on two-phase immersion cooling via pool boiling employing single-fluid and multi-fluids in the system. In the proposed multi-fluid system, two immiscible fluids are stacked in series without a solid interface separating them. NOVEC 7100 is used as the boiling fluid where the heater is fully immersed, and deionised water serves as the condensing fluid. The results show that both single and multi-fluid immersion cooling systems are able to effectively cool high-power electronic devices. However, the multi-fluid system demonstrates superior cooling performance compared to the single-fluid system, owing to its enhanced heat transfer capabilities. The multi-fluid system has a superior overall heat transfer coefficient, with an average increase of 33.3% compared to the single-fluid system. The findings of this study contribute to the understanding and optimisation of future multi-fluid two-phase immersion cooling systems.