King Charles III experienced the effects of the United Kingdom's hottest June day on record, requiring assistance to stay cool during engagements in London. On Wednesday, as temperatures reached a provisional 35.7 degrees Celsius (96.3 degrees Fahrenheit), the King was seen being fanned by a senior aide while greeting delegates.

The incident occurred at St. James's Palace during an environmental reception focused on super pollutants, held as part of London Climate Action Week. Retired Vice Admiral Sir Tony Johnstone-Burt, Master of the Household, used an electric fan to help the King cope with the heat inside the historic building, which lacks air conditioning. Guests at the reception were also provided with folding fans, and a nurse was on standby.

Energy Secretary Ed Miliband, addressing the attendees, noted the record temperatures, stating that such heat "didn't used to be normal, but unfortunately it is now the new normal." He emphasized the urgency of addressing climate change and reducing emissions.

Later in the day, King Charles visited the Roger Gracie Brazilian Jiu Jitsu Academy in Hammersmith, where he learned about the charity REORG's work supporting military personnel and veterans. During the visit, he observed demonstrations, spoke with the charity's founder, and was presented with a white belt. He also presented a black belt to a student.

Earlier, the King had met with members of the Afghan Refugee Women's Cricket Team at Clarence House. He listened as the players shared their experiences of escaping Afghanistan following the Taliban's return to power. The team, in the UK for a series of matches, gifted the King a decorated cricket bat.