The heatwave that scorched Britain in June 2026 was not just uncomfortable: it was expensive. Researchers at LSE's Grantham Research Institute on Climate Change and the Environment, working with the Euro-Mediterranean Center on Climate Change, surveyed a nationally representative sample of 1,950 adults about how the heat affected their work and sleep. Scaling the responses to the workforce, they estimate around 24 million working hours were lost, costing the economy about 1.15 billion pounds.
The losses came through two channels: shortened working days and days not worked at all. Some 3.6 per cent of respondents, equivalent to roughly 1.25 million workers, reported not working at all during the heatwave week because of the heat. Fully 87 per cent of workers reported at least one health-related impact that week, and the researchers valued lost hours using Office for National Statistics output figures of about 48 pounds per hour.
The authors stress the estimate is likely conservative, since it excludes reduced effort while at work, which about a third of respondents reported. The study's wider message, set out in the institute's accompanying work on climate change's heat tax on the UK labour force, is that Britain remains insufficiently adapted to the climate it now has, and that investment in adaptation, from cooler buildings to flexible working practices, has a hard economic rationale.