The Office Shops and Railway Premises Act 1963 established a crucial precedent by setting a minimum workplace temperature of 16°C for office work, representing one of the earliest statutory recognitions that workplace temperature directly affects worker health and safety12. However, as climate change intensifies and heatwaves become increasingly frequent across the UK, the legal framework has struggled to adapt to the new reality of excessive heat presenting as significant an occupational hazard as cold conditions. This report examines the evolution of workplace temperature law, parliamentary debates, legal cases, and the ongoing campaign for maximum temperature limits in an era of climate emergency.

Historical Foundation and Legislative Development

The legislative journey of workplace temperature regulation reveals a legal framework that established comprehensive minimum standards but has notably failed to evolve maximum temperature protections despite mounting scientific evidence and parliamentary pressure.

The Factories Act 1961 consolidated previous factory legislation and established that “a temperature of less than sixty degrees [15.6°C] shall not be deemed, after the first hour, to be a reasonable temperature while work is going on”34. This was complemented by the Offices, Shops and Railway Premises Act 1963, which set similar standards for office workers, establishing 16°C as the minimum reasonable temperature for work not involving severe physical effort12.

These Acts represented significant progress in worker protection, moving beyond the previous patchwork of regulations to establish clear, enforceable standards. However, both pieces of legislation were explicitly designed to address cold working conditions – the primary concern in an era before climate change made extreme heat a regular occupational hazard5.

The Health and Safety at Work Act 1974 transformed the regulatory landscape by establishing general duties of care, requiring employers to ensure “so far as is reasonably practicable, the health, safety and welfare at work” of employees6. This Act created the framework within which modern temperature-related obligations operate, though it deliberately avoided prescriptive temperature limits.

The current regulatory framework rests primarily on the Workplace (Health, Safety and Welfare) Regulations 1992, which require employers to maintain “reasonable” indoor temperatures while providing no specific maximum limits6. The accompanying Approved Code of Practice suggests minimum temperatures of 16°C for sedentary work and 13°C for physically demanding work, but conspicuously provides no upper temperature guidance78.

The Current Legal Vacuum: No Maximum Temperature Protection

Despite sixty years of legislative development since the 1961 Acts, UK law provides no statutory maximum workplace temperature. The Health and Safety Executive explicitly states that “there is no law for maximum working temperature, or when it’s too hot to work”910. This creates a stark contrast with the comprehensive minimum temperature protections established in the 1960s.

The HSE’s position that “every workplace is different” and that “no meaningful upper limit can be imposed because in many indoor workplaces, high temperatures are not seasonal but created by work activity, for example in bakeries or foundries”1112 has become the standard governmental response to calls for maximum temperature legislation. However, this reasoning fails to account for the fact that many countries successfully operate workplace-specific maximum temperature limits.

The TUC has consistently called for maximum indoor working temperatures of 30°C, or 27°C for strenuous work1113, while Unite union proposes that employers must take action when temperatures exceed 24°C7. Usdaw recommends a 25°C maximum8, and the World Health Organization suggests 24°C as a maximum working temperature14. These proposals demonstrate that specific maximum temperatures are both technically feasible and widely supported by health and safety experts.

Research indicates that workplace accidents increase by 5% to 7% when temperatures rise above 30°C and by 10% to 15% when temperatures exceed this threshold15. Studies of heat-related workplace injuries show dramatic increases when temperatures rise above 80°F (26.7°C), with heat-related claims increasing seven times when daily maximum temperatures reach 90-95°F (32-35°C)16.

Parliamentary Debates and Political Response

Parliamentary engagement with workplace temperature regulation reveals a consistent pattern of cross-party concern met with government resistance, despite mounting evidence of climate change impacts on worker safety.

Early Parliamentary Interest (2009-2016)

Parliamentary interest in workplace temperature limits can be traced to 2009 parliamentary questions about heat stress in the workplace1718. MPs Paul Rowen and others raised concerns about workplace temperature standards, with the HSE reporting minimal prosecutions for temperature-related failures – only one prosecution between 2004-2008 related to workplace heat stress17.

In 2016, Labour MP Ian Mearns led the first significant parliamentary push for maximum workplace temperatures, proposing statutory limits of 30°C generally and 27°C for strenuous work19. Mearns, who chairs the influential business committee of back-bench MPs and the bakers’ union group in Parliament, argued that “normal cooling systems just can’t cope” with increasing temperatures and warned of serious health risks for workers, particularly those working with machinery19.

The 2022 Parliamentary Breakthrough

The most significant parliamentary development occurred during the unprecedented July 2022 heatwave, when the UK recorded its first-ever temperatures above 40°C. A cross-party Early Day Motion proposing maximum workplace temperatures attracted 55 MP signatures20, representing the strongest parliamentary support for temperature limits to date.

The July 2022 Early Day Motion called for “legislative proposals to ensure a maximum working temperature of 30 degrees Celsius, or 27 degrees Celsius for those doing strenuous work, beyond which employers would have a statutory duty to introduce effective control measures”20. The motion noted that “high temperatures are one of their top concerns” among workplace health and safety representatives and highlighted that consequences range from “dizziness, tiredness, asthma, throat infections and, in extreme cases, heat stroke and death”20.

However, the Conservative government’s response was dismissive. Cabinet Office minister Kit Malthouse rejected calls for maximum temperatures, citing the difference between offices and blast-furnace facilities as justification for maintaining the status quo21. Malthouse argued that “circumstances may change, so if you are working in front of a blast furnace that is different from working in an office”21, ignoring the fact that workplace-specific regulations could easily address such variations.

House of Lords Engagement (2025)

Recent parliamentary activity demonstrates continued high-level concern about heat-related workplace risks. In June 2025, the House of Lords debated UK extreme heat preparedness, with peers highlighting that “prolonged extreme heat is now 100 times more likely because of climate change”22. During the debate, a peer asked whether the government would “consider asking colleagues to commission the Health and Safety Executive to conduct a fresh review of the evidence and assess whether it is time for a maximum working temperature in the UK”22.

The government’s response remained non-committal, with the Minister acknowledging ongoing conversations about workplace temperature but providing no concrete commitments to legislative change22.

Labour Government Promises and Recent Developments

The Labour Party’s 2024 election manifesto included specific commitments to “modernise health and safety guidance on extreme temperatures”232425. The party’s “Plan to Make Work Pay: Delivering A New Deal for Working People” explicitly recognized that “in a number of sectors working temperatures are regularly unacceptably high, including for those working in strenuous and sedentary jobs, causing serious health and safety concerns”25.

Labour committed to “modernising health and safety guidance with reference to extreme temperatures, preventative action and steps to ensure safety at work”25. This represented the first time a major political party had included workplace heat protection in its manifesto, reflecting growing recognition of climate change impacts on occupational health.

However, early indications from the Labour government suggest a cautious approach to implementation. In July 2025, Business Secretary Jonathan Reynolds dismissed calls for new workplace legislation on extreme heat26. When asked whether workers should be sent home when temperatures become too high without adequate mitigation, Reynolds argued that “behavioural changes” like drinking water and sun protection were more important than additional legal frameworks26.

Reynolds stated: “There are existing laws in place, the health and safety acts, around what a safe workplace should be. I don’t think we need more legislation in that area”26. This response suggests the Labour government may retreat from its manifesto commitments, despite mounting evidence of climate change impacts on worker safety.

Legal Cases and Enforcement Challenges

The absence of specific maximum temperature legislation has created significant challenges for legal enforcement and compensation claims, though some notable cases demonstrate the potential for successful litigation under existing health and safety frameworks.

Employment Tribunal Cases

The Employment Appeal Tribunal case of Miss J Browne v The Commissioner of Police of the Metropolis provides insight into how workplace temperature issues are addressed through employment law27. The case involved a police employee who suffered asthma exacerbations due to poor environmental conditions in an open-plan office where “windows throughout the building were sealed for security” and “ventilation was provided through an air conditioning and heating system which could not be operated manually by staff”27.

The tribunal made important findings about workplace environmental control, noting that the employee “had no control over ambient temperatures anywhere” except through use of “a personal heater or fan”27. While this case primarily concerned ventilation and employee health adjustments rather than extreme heat, it demonstrates how existing employment law can address temperature-related workplace health issues.

Personal Injury Compensation

A significant compensation case awarded £20,000 to an engineer who developed severe cold injuries from prolonged exposure to temperatures between -20°C and -70°C while working in a freezer complex28. The case established important precedents for temperature-related workplace injury claims, with the judge awarding additional compensation for disadvantage in the labour market28.

While this case involved extreme cold rather than heat, it demonstrates that UK courts will award substantial compensation for temperature-related workplace injuries when employer negligence can be established28. The case suggests that similar principles could apply to heat-related injuries if maximum temperature duties were established.

HSE Prosecution Patterns

HSE prosecution data reveals minimal enforcement action on temperature-related workplace failures. Between 2004-2008, the HSE brought zero prosecutions specifically for employers’ failures to manage high temperatures in the workplace17. However, the HSE noted that “legal proceedings have recently been initiated by HSE related to a workplace fatality in 2006-07 in which heat stress was implicated”17.

In 2010, a retailer was fined £2,000 plus costs by Carlisle County Council for providing insufficient heating in the workplace, with temperatures falling as low as 7.6°C despite an improvement notice29. This case demonstrates that enforcement action is possible under existing regulations when minimum temperature requirements are breached, but no equivalent maximum temperature enforcement framework exists29.

Schools and Educational Settings: Specialized Challenges

Schools face particular challenges in managing extreme heat due to their specific legal obligations, vulnerable populations, and often inadequate infrastructure designed for a cooler climate.

Educational Temperature Requirements

Schools in England must maintain minimum temperatures of 18°C in ordinary classrooms and 16°C in other teaching areas303132 under the School Premises Regulations. These requirements are more stringent than general workplace minimums, reflecting the particular needs of children and the learning environment.

However, schools face the same absence of maximum temperature protection as other workplaces. The Department for Education explicitly states that “we don’t normally advise schools to close” during hot weather, emphasizing that “school attendance is the best way for pupils to learn and reach their potential, and hot weather can usually be managed safely”3334.

Heat Management Strategies

During the unprecedented July 2022 heatwave when UK temperatures exceeded 40°C for the first time, the DfE advised against school closures but acknowledged that children were at increased risk of heat-related health effects3435. The government provided guidance including encouraging pupils to wear “loose, light-coloured clothing,” avoiding vigorous physical activity when temperatures exceed 30°C, and ensuring adequate hydration3436.

Analysis by Schools Week found that 104 schools closed during the July 2022 heatwave despite government advice to remain open34. This demonstrates the practical reality that extreme heat can make educational environments unsafe, regardless of official guidance encouraging schools to remain open.

Educational Health Impacts

Research demonstrates significant learning impacts from excessive classroom temperatures. The National Association of Schoolmasters Union of Women Teachers (NASUWT) notes that excessive classroom temperatures are “not only uncomfortable, but they are also a health and safety hazard” and that “excessive heat in classrooms has been shown in many studies to impact on pupils’ learning, with a 1°C increase in temperatures linked to a 2% decline in learning”14.

Studies indicate that “each additional school day with a temperature in the 30s (°C) reduces pupil achievement by one sixth of a percent of a year’s worth of learning” and that “disadvantaged pupils also suffer up to three times the impact of excessive temperatures than other pupils”14. This evidence suggests that the absence of maximum temperature protections in schools may be exacerbating educational inequality.

The World Health Organization recommends a maximum temperature of 24°C for optimal learning environments14, significantly lower than the 30°C maximum proposed for general workplaces. However, UK schools operate without any statutory maximum temperature protection, relying instead on head teacher discretion and non-binding guidance.

International Comparisons and Best Practice

The UK’s failure to establish maximum workplace temperatures places it behind many other jurisdictions that have implemented comprehensive heat protection frameworks.

Spain requires that places where sedentary or light work takes place must be maintained between 17°C and 27°C21, providing both minimum and maximum protection for workers. China obligates employers to reduce working hours and work intensity when temperatures exceed 35°C outdoors and 33°C indoors, and to suspend outdoor work if temperatures reach 40°C15.

Thailand uses wet bulb globe temperature to determine limits for different intensities of physical work: 34°C for light work, 32°C for moderate work, and 30°C for heavy work15. The UAE operates a mandatory three-month ‘midday break’ for outdoor workers, prohibiting work in open spaces from 12:30 to 3:00 PM during hot summer months15.

Ontario introduced heat stress legislation in 2023 under its Occupational Health and Safety Act, setting heat stress exposure limits depending on work intensity15. These international examples demonstrate that workplace-specific maximum temperature limits are both technically feasible and legally enforceable.

Economic and Health Impacts

The economic case for maximum temperature regulation is compelling. The Environmental Audit Committee found that interrupted sleep patterns due to high temperatures can cost the UK economy £60 billion annually, representing 1.5% to 2% of GDP37. Work-related injuries increase substantially during hot weather, and the “silent killer” of heatwaves could claim up to 10,000 lives annually in the UK without concerted action37.

Research demonstrates that suicide risk is twice as high when temperatures reach 32°C compared to 22°C37, highlighting the broader mental health impacts of extreme heat. The summer of 2023 saw 2,295 deaths associated with five intense heat periods, while September 2023 witnessed a 552% rise in NHS visits for heat exhaustion and heatstroke information38.

Workers’ compensation data from Pennsylvania shows that heat-related claims increased by 36% as the average number of days exceeding 80°F rose from 51 to 62 days annually39. The data indicates that 90% of heat-related workers’ compensation claims occur when temperatures exceed 80°F (26.7°C), with 56% occurring above 90°F (32.2°C)16.

Current Campaigns and Union Activity

Trade unions continue to campaign vigorously for maximum temperature legislation. Unite union has been campaigning for maximum working temperatures for more than 20 years, calling for legal obligations requiring employers to take action when indoor temperatures exceed 24°C and absolute maximums of 30°C generally and 27°C for strenuous work15.

Rob Miguel, Unite’s national health and safety adviser, argues that “until that legal protection is in place, employers will always point to the fact that there’s no upper limit”15. Unite emphasizes that “at a time when climate change is making extreme heat an increasingly pressing concern, it’s particularly worrying that we’re falling behind EU countries in terms of protection levels”15.

The TUC continues to call for an absolute maximum indoor working temperature of 30°C, or 27°C for those doing strenuous work1113. The union federation argues that this “is intended as an absolute maximum rather than an indication that regular indoor work at just below 30°C would be acceptable”40.

Usdaw has welcomed Labour’s commitment to modernizing health and safety guidance on extreme temperatures, with General Secretary Paddy Lillis stating that “hot weather makes working conditions difficult for too many” and emphasizing the union’s long-standing campaign for heat stress protection25.

Conclusion and Future Prospects

The legal landscape of UK workplace temperature regulation presents a striking paradox: comprehensive minimum temperature protections established over sixty years ago, coupled with a complete absence of maximum temperature limits despite mounting evidence of climate change impacts on worker safety and productivity.

The Office Shops and Railway Premises Act 1963 and Factories Act 1961 established minimum temperature standards that remain largely unchanged today, demonstrating that specific, enforceable temperature limits are both legally feasible and practically effective124. The success of these minimum standards undermines arguments that workplace temperature limits are inherently unworkable due to workplace diversity.

Parliamentary engagement reveals significant cross-party support for maximum temperature legislation, with 55 MPs supporting the 2022 Early Day Motion for 30°C maximum temperatures20. However, successive governments have resisted these calls, often citing spurious arguments about workplace diversity that could easily be addressed through differentiated standards.

The Labour government’s manifesto commitment to “modernise health and safety guidance on extreme temperatures” raised expectations for substantive reform232425. However, early signals from Business Secretary Jonathan Reynolds suggest the government may retreat from these promises, prioritizing “behavioural changes” over legislative protection26.

The absence of maximum temperature legislation leaves UK workers increasingly vulnerable as climate change intensifies. The Environmental Audit Committee’s warning that heatwaves could claim 10,000 lives annually without action37 demonstrates the urgency of legislative reform. The economic costs of inaction – £60 billion annually from heat-related productivity losses37 – far exceed the implementation costs of comprehensive temperature protection.

For schools, the situation is particularly concerning given evidence that excessive temperatures reduce learning outcomes and disproportionately impact disadvantaged pupils14. The DfE’s resistance to heat-related school closures, despite 104 schools closing during the July 2022 heatwave34, reveals the inadequacy of current guidance in protecting vulnerable populations.

The legal framework established in the 1960s provides a clear template for reform. Just as the Offices, Shops and Railway Premises Act 1963 recognized that 16°C represented a reasonable minimum temperature for office work1, modern legislation could establish that 30°C (or 27°C for strenuous work) represents a reasonable maximum for worker safety.

International best practice demonstrates that comprehensive heat protection is both achievable and effective. Spain’s 17-27°C range for sedentary work, China’s mandatory work restrictions above 35°C, and Ontario’s 2023 heat stress legislation2115 provide proven models for UK implementation.

The current legal vacuum cannot persist as climate change makes extreme heat an increasingly frequent occupational hazard. The question is not whether maximum temperature legislation will be necessary, but whether the UK will act proactively to protect workers or wait for a heat-related workplace fatality to force legislative change. The comprehensive minimum temperature protections established in 1963 demonstrate that the UK once led the world in workplace temperature regulation – it is time to reclaim that leadership by extending the same protection to workers facing the opposite extreme.