Saudi Arabia on Monday warned of a temperature spike in Mecca as Muslim pilgrims wrapped up the hajj in searing conditions, with more than a dozen heat-related deaths confirmed. One of the world’s largest religious gatherings unfolded during the oven-like Saudi summer again this year, and authorities recorded more than 2,700 cases of “heat exhaustion” on Sunday alone, the Saudi health ministry said. On Monday, according to the Saudi weather service, temperatures reached 51.8 degrees Celsius (125 degrees Fahrenheit) at Mecca’s Grand Mosque, where pilgrims were circling the Kaaba, the large blac…