The report updated earlier estimates to account for four distinct heatwaves recorded between May and late July 2026, Anadolu Agency reported.
May's early heatwave resulted in roughly £500 million in damage, while peak temperature episodes in June and July led to losses of £2.36 billion and £1.5 billion, respectively.
Analysts' calculations showed that each one-degree Celsius rise above 30 degrees Celsius in Europe reduced average hourly worker output by 3%.
Researchers projected cumulative annual UK productivity losses reaching £25.6 billion by 2030 if extreme heat trends continue at the current pace.
To mitigate future losses, the think tank recommended establishing a national maximum working temperature, introducing a heat insurance scheme and expanding investments in urban cooling infrastructure.