This study numerically evaluates PCMs in fabric-based emergency tents in Sistan and Baluchestan, Iran, using a passive thermal-management strategy for hot desert conditions. A two-stage CFD framework is applied: steady-state external airflow is solved with the SST k-omega turbulence model in ANSYS Fluent to obtain surface convective coefficients, while transient heat transfer inside the tent is computed via the enthalpy-porosity (mushy-zone) method, incorporating solar radiation, phase change, and buoyancy effects. Models were validated against benchmark data for PCM melting, external forced convection, and natural convection (similar to 7% deviation), confirming simulation reliability in capturing coupled thermal phenomena. Results show that PCM integration reduces the maximum indoor temperature from 326.75 K to 312.25 K (14.5 K/4.4% lower) and the daily average from 317.89 K to 308 K (9.89 K/3.1% lower). The peak vertical temperature difference decreases by 31%, from 17.24 K to 11.88 K. Roofs fully melted, with the West Roof storing 23.85 MJ and other PCM layers storing 16.08-19.33 MJ, while the West Wall reached similar to 60% melting, yielding a total of 71.55 MJ of latent heat storage, more clearly capturing the system's overall thermal behavior. Internal air velocities remained below 0.03 m & centerdot;s(-1), indicating limited natural mixing.