In the aerospace industry, components are often complex and operate under extreme thermal conditions. These conditions generate significant heating and cooling demands—collectively known as thermal loads—which must be accurately replicated during testing. To properly test these components, a system is needed to replicate the heating and cooling conditions they experience. The Portable Thermal Load Cart is a specialized system designed to continuously simulate these thermal loads by removing or adding heat at the component's exit, then feeding the conditioned fluid back to the inlet at predefined inlet conditions. Developed to enhance Triumph Engine Control Systems’ testing capabilities, this portable solution replaces an outsourced stationary load cart, providing improved flexibility and efficiency in thermal load delivery. To replicate the aircraft heat sink and load, the system uses hot and cold fluid loops, engineered to meet specific temperature and flow requirements. To meet Triumph’s needs, the final design is modular, ensuring cost-effectiveness and adaptability across various testing environments.