Saturday was the hottest day in three years for Northern Ireland and Wales, and the hottest in two years in Scotland – while England’s highest temperature was 33.1C recorded in Ross-on-Wye, in Herefordshire.
The heat led to disruption on the train network in Wales – leaving thousands of Stereophonics fans facing cancellations – while fire crews in Perth in Scotland spent a second day battling a wildfire.
People across the country flocked to beauty spots and bodies of water on Saturday to keep cool.
The death of the 15-year-old boy in the River Kelvin came just hours after a woman, 63, died after falling near a waterfall north of Glasgow.
Fire officials warn of an increased risk of drowning when trying to keep cool, urging parents to supervise children around water at all times.
