Anyone walking barefoot around the Kaaba in peak summer feels the intense heat but notices the marble floor is not hot. The courtyard is paved with Thassos marble, a light-colored stone known for high solar reflectance and low heat absorption. Unlike darker materials, it reflects much sunlight, keeping surface temperatures lower than concrete or asphalt, even in direct sun. A 2022 study in the Journal of The Institution of Engineers (India) Series D found Thassos marble has higher thermal conductivity than normal white marble. This spreads heat efficiently through the stone instead of letting it gather on the surface. The stone’s unique microstructure and minerals boost its reflectivity and heat distribution. Another 2021 study on the marble at the Grand Mosque in Makkah used local weather data and thermal modelling. It confirmed that the marble’s high reflectance greatly lowers surface temperatures and helps keep barefoot pilgrims comfortable. The marble slabs are thick and placed over special insulating layers with air spaces. This setup moves heat away from the surface. The open-air design of the mosque also allows airflow, while continuous movement of worshippers improves cooling near the ground. What looks like simple stone is a smart thermal system. The combination of reflective marble, good heat flow, insulation, and airflow controls temperature in one of the world’s hottest places, making it safe and pleasant for worshippers.