The UK has no maximum workplace temperature, so employers are setting one by default

A survey of 1,288 UK workers across seven climate-exposed sectors found that 56% had been affected by at least one extreme weather event at work in the previous 12 months, while only 26% said their employer had a climate adaptation or extreme-weather plan ^[1][2][3]. In June the Health and Safety Executive urged employers to make sure workers were protected from heat, but did not define what "too hot" means, and no UK law sets a maximum permitted workplace temperature ^[4][5].

Those two facts together describe an unusual regulatory position. The regulator has asserted a duty without a number ^[4], and Parliament has not supplied one ^[5]. The practical effect is that the threshold at which work stops gets written at site level, by whoever is on shift, and the consequences of getting it wrong sit with the employer.

The survey, reported by phys.org and covering agriculture, construction, education, emergency services, entertainment and sports, transport, and health and social care, indicates that the absorbing is already happening informally ^[2][6]. Among workers who had taken weather-related sick leave, 40% cited heat as a factor ^[6]. Of those affected by extreme weather, 72% said extreme heat had harmed their well-being and 44% said the same of drought ^[7][8]. Heat is not the whole exposure: flooding, storms, snow and ice, and air-pollution-related conditions all appear ^[9].

The operational numbers are the ones worth reading twice. Some 44% of respondents said they had changed working patterns because of extreme weather ^[10]. Half of affected workers had to reduce working time, 18% stopped because their employer suspended operations, and 14% took time off ^[11][12][13]. That is capacity coming out of the schedule whether or not anyone has planned for it. Meanwhile 30% of workers said they had received training on managing weather impacts at work, which leaves 70% who had not ^[14][1]. On plans, 74% reported none ^[2].

Exposure is not evenly spread. Workers in agriculture, emergency services, and transport and logistics reported the highest exposure across all weather categories ^[15], and emergency services was the sector where most workers felt their employer was not doing enough ^[16]. Applied to the sample, 56% is roughly 721 of the 1,288 respondents ^[3].

The background trend is not in dispute. The decade from 2015 to 2024 was 10% wetter and 1.24C warmer than the 1961-1990 baseline, three recent years rank among the five warmest on record, and 40C was exceeded in July 2022 for the first time since the mid-19th century ^[17][18]. Broader estimates for climate-induced weather hazards, covering flood damage, failed infrastructure and falling productivity, point to a GDP decline of 3% to 7%, though the authors note there is no full UK estimate yet ^[19].

There is also a measurement gap that matters for anyone trying to price this. According to the authors, there has been no comprehensive analysis of the short- and long-term health impacts of the 2022 heat waves on UK workers ^[20], and the Climate Change Committee's recent risk assessment largely overlooked workers ^[21].

Watch the Trades Union Congress campaign for the HSE to introduce a maximum workplace temperature in line with international guidance ^[22]. A published figure would convert a duty of judgment into a compliance test, which changes what employers must record, when they must stand work down, and what an absence claim looks like afterwards.