UK workplace heat limits gain political momentum despite government resistance
London's mayor is backing proposed maximum workplace temperatures, adding pressure on the UK government to impose new heat regulations that could reshape operating costs for businesses and public services.
Sadiq Khan, the mayor of London, has thrown his support behind establishing a legal maximum temperature for workplaces. The move increases political pressure on the national government to update labour safety laws as repeated heatwaves disrupt the UK economy and public services.
For businesses, a legally binding heat limit would likely require significant capital investment in cooling infrastructure. Unions including Unison and the Trades Union Congress are demanding a threshold of 30C, dropping to 27C for strenuous work, which would force employers across retail, manufacturing, and logistics to upgrade ventilation and air conditioning systems.
The push follows severe infrastructure failures during recent heatwaves, with temperatures exceeding 40C in some workplaces. The June heatwave alone killed an estimated 440 people daily at its three-day peak, while failing IT systems, broken MRI scanners, and stalled hospital cooling units highlighted the vulnerability of critical economic and public health assets.
Khan lacks the authority to enforce such a rule in the capital, but his endorsement signals growing alignment among local leaders. Green party MP Hannah Spencer is preparing to introduce a bill in parliament to create a workplace heat limit. In May, the government’s official Climate Change Committee also recommended maximum temperature regulations to protect workers and incentivize the deployment of necessary cooling.
Local officials argue the economic burden of inaction falls disproportionately on certain communities. Zoë Garbett, the Green party mayor of Hackney, said the crisis is a matter of social justice, noting that headteachers face impossible choices between keeping schools open in dangerous heat or closing them when children lack cool alternatives at home.
“Urgent investment from the government in more resilient schools and public buildings isn’t just an issue of the climate crisis, it’s a matter of basic social justice,” Garbett said. She added that councils need statutory duties and proper funding to act.
The national government currently maintains a firm stance against new mandates. “The Health and Safety Executive (HSE) has shared guidance for employers to plan for and support those working in extreme heat to keep workers healthy and safe,” a government spokesperson said, stating there are “no plans to introduce a mandatory maximum workplace temperature.”
However, the government confirmed the HSE will launch a public consultation later this year on workplace health and safety that will review temperature thresholds, leaving the door open for future regulatory shifts.
