Passive thermal energy storage materials are increasingly recognized as cost-effective solutions for reducing cooling energy demand in regions with extreme heat. Organic phase change materials (PCMs), particularly paraffin wax, offer strong thermal buffering performance due to their high latent heat capacity. However, their inherently low thermal conductivity and limited structural stability reduce practical efficiency in passive cooling systems. This study aims to develop and evaluate mineral-enhanced organic PCM composites by incorporating UAE-derived minerals—specifically limestone, dolomite, silica sand, and gabbro fines—to improve heat transfer and mechanical integrity. Organic PCM composites will be prepared using paraffin wax blended with varying mineral loadings (5–25 wt%). Samples will be fabricated using simple casting techniques, and their thermal performance will be characterized through controlled hot-plate heating (≤90 °C), embedded thermocouple measurements, and cooling cycle experiments. Key evaluation parameters include melting and solidification behavior, heat absorption and release characteristics, thermal conductivity enhancement, and dimensional stability during repeated thermal cycling. It is anticipated that UAE minerals—particularly silica sand and dolomite—will significantly improve the thermal conductivity and stability of the PCM matrix. The expected outcomes will help identify safe, low-cost, and locally sourced mineral–PCM combinations suitable for passive cooling applications in building envelopes, rooftop thermal buffers, and compact thermal energy storage units. This proposed study demonstrates the potential of leveraging abundant UAE mineral resources to create sustainable, climate-adapted thermal energy storage materials for extreme desert environments.