<p>Groundwater levels in Beijing, China, are rising, increasing demand for anti-floating design in underground structures. In the context of combining shallow geothermal energy use with anti-floating needs, improving the design and ensuring the safety of energy tension piles require a better understanding of their thermo-mechanical behavior. This study, based on the Tsinghua University Science Museum project in Beijing, uses full-scale field tests and theoretical analysis to examine the thermo-mechanical response and uplift capacity of piles under combined temperature and mechanical loads. Results indicate that cooling increases the maximum tensile stress in the pile by approximately 30%, while heating changes the stress state from pure tension to a combined tension–compression state. Both thermal conditions shift the critical section location. A key finding is the strong impact of rapid heating on uplift capacity: Excess pore water pressure (EPWP) from rapid heating reduces the soil’s effective stress and shear strength. This weakening effect was quantified using the Campanella–Mitchell pore pressure model and Method A-based undrained shear strength, revealing an approximate 15% reduction in ultimate uplift capacity. The results show that rapid heating is a non-negligible risk factor in energy tension pile design. Ultimately, this research proposes a dual-control paradigm, providing a solid theoretical basis and identifying risks for the safe design and use of such energy piles.</p>