Extreme heat events in the Middle East have become increasingly frequent and intense due to human-driven climate change. During the Hajj pilgrimage in Mecca, Saudi Arabia, in June 2024, temperatures soared to a record-breaking 51.8 °C, resulting in the tragic deaths of at least 1300 pilgrims and over 2700 non-fatal injuries. Considering that the intensity and persistence of this heatwave exceed all recorded analogues in the available historical record, it may be considered statistically unprecedented within the context of the observed climate. Our analysis suggests that the exceptional event of June 2024 represents typical extreme conditions towards the second half of the century if current trends continue. The record-breaking temperature of nearly 52 °C illustrates the potential threats climate change could pose to major outdoor gatherings, such as the Hajj pilgrimage, under business-as-usual scenarios. Addressing these challenges through effective climate mitigation and adaptation is essential to building resilience against future extreme heat risks.