There's no legal maximum temperature at which work in the UK has to stop.
Most people — including many employers — don't know that.
The Workplace (Health, Safety and Welfare) Regulations 1992 set a minimum working temperature of 16°C, or 13°C where the work is strenuous. The upper end has no equivalent figure written into law. The legislation simply requires the temperature to be "reasonable" — a word that becomes increasingly difficult to defend when it's 34°C in a warehouse with no mechanical ventilation.
That may be about to change.
What Parliament Heard This Week
Sir Stephen Timms, Minister for Social Security and Disability, confirmed in Parliament this week that HSE is progressing a wider review of the Approved Code of Practice (ACOP) for the Workplace (Health, Safety and Welfare) Regulations 1992 — including the sections relating to workplace temperature. A public consultation is expected to follow later this year.
The announcement came against the backdrop of the UK's third heatwave of 2026. The Met Office confirmed this week that the UK has now recorded eight days of temperatures at or above 34°C in 2026 — the highest number ever on record.
What the Unions and Safety Bodies Are Calling For
Unions including Unison and the TUC have renewed their longstanding calls for a legal maximum indoor working temperature of 30°C, or 27°C for strenuous work. A separate parliamentary petition calling for a legally binding maximum of 25°C for all workplaces gathered over 6,000 signatures this week.
The British Safety Council has called for the Workplace Regulations to be updated to include explicit protections against excessive heat and cold, supported by statutory guidance that establishes practical trigger temperatures and proportionate control measures.
What Employers Need to Know Right Now
Whatever emerges from the consultation, the legal position for employers under existing legislation is already clear.
The Management of Health and Safety at Work Regulations 1999 require employers to carry out suitable and sufficient risk assessments covering all significant hazards — including thermal comfort and heat stress. Heat is a workplace hazard. The absence of a specific maximum temperature in the Regulations does not remove the duty to assess and control it.
HSE has also issued specific guidance for employers on managing the risk from extreme heat, which applies now, regardless of where the ACOP review lands.
Practical steps employers should be taking in hot weather include:
- Reviewing risk assessments to include heat as a specific hazard for relevant roles
- Providing access to cool drinking water
- Allowing additional rest breaks during hot periods
- Considering adjustments to shift patterns or working hours where feasible
- Ensuring adequate ventilation, fans, or cooling in indoor workspaces
- Monitoring workers in high-risk roles — those doing physical work outdoors or in hot environments
The Broader Picture
The ACOP review is significant not just because of the current heatwave. The UK workforce is working in conditions that the original 1992 Regulations were not designed for — climate patterns have changed, working environments have changed, and the expectation of what "reasonable" looks like has shifted.
Whether or not a specific maximum temperature is ultimately written into law, the direction of travel from regulators and government is clear. Businesses that haven't already treated heat as a managed workplace hazard should treat the coming consultation as a prompt to get that in order now, rather than after new guidance lands.
If you need support reviewing your risk assessments or updating your health and safety documentation, RiskCompli can help you build site-specific, legally compliant documentation without starting from scratch.
Source: British Safety Council, 9 July 2026. Parliamentary statement by Sir Stephen Timms, Minister for Social Security and Disability.