Do we need a Maximum Temperature for the UK Workplace?

Some people are getting a little hot under the collar because we don't have a maximum temperature for the UK workplace – do we need one?

It’s that time of the year when the tabloids lead with headlines like It’s Too Hot To Work, Turning up the heat at Work, Office Meltdown etc when it’s a short of news day but this year they probably have more relevance with the latest heatwaves. As temperatures continue to climb the thermometer scale the old chestnut arises – Why don’t we have a maximum workplace temperature?

While employers have legal duties to protect the health, safety and welfare of their employees, there is currently no specific upper temperature limit in UK law. For many workers, particularly those in offices, warehouses, factories and kitchens, that can seem difficult to understand when the mercury starts pushing into the high twenties and beyond. So, do we need a maximum workplace temperature, or is the current approach sufficient?

The Current Legal Position

Under UK health and safety legislation, namely Reg 7 Workplace Health, Safety & Welfare Regs 1992 and accompanying ACOP (paragraphs 60-68) employers must ensure that workplace temperatures are "reasonable". The law does provide an example of what a reasonable temperature might be—typically 16°C for most indoor workplaces, or 13°C where strenuous physical work is undertaken. No maximum temperature is currently indicated.

As part of the ‘Make Work Pay’ programme, the government has committed to ‘modernise health and safety guidance with reference to extreme temperatures’  and is reviewing the Workplace Regulations 1992. The Health and Safety Executive (HSE) is currently consulting on Approved Code of Practice (ACOP) updates. The Trades Union Congress (TUC) is actively campaigning for maximum temperature caps (e.g., stopping work above 30^O. There is a petition by the Green Party currently gaining support (needing another 2,500 signatures for the Government to respond to it) who want the Government to set a strict limit of 25°C for both indoor and outdoor work. When temperatures hit 25°C, employers must legally provide cooling measures or pause work. The law must also enforce lower thresholds for more physical roles.

The HSE treats excessive heat as a workplace hazard. Under existing rules, employers must conduct risk assessments and implement practical steps to manage thermal comfort. Current official guidance suggests that employers:

• Ensure adequate ventilation and shade

• Provide constant access to drinking water

• Permit more frequent breaks

• Offer flexible working hours or casual dress codes

• Supply outdoor workers with appropriate sunscreen and protective clothing.

  
  

The Challenges of Setting a Limit

At first glance, establishing a maximum temperature sounds simple but the reasoning why not one so far is relatively straightforward. Different workplaces operate under vastly different conditions. An office environment at 30°C presents a different level of risk compared to a commercial bakery, foundry, glass manufacturing facility or industrial kitchen where higher temperatures are part of the process. A single temperature limit may therefore be difficult to apply universally. So not necessarily just a case of setting the limit at 30°C and close workplaces above that threshold. The reality is more complicated.

Also temperature alone does not tell the full story. Factors such as:

• Humidity

• Air movement

• Physical workload

• Exposure duration

• Clothing and personal protective equipment

• Individual health conditions

all influence how heat affects workers.

For example, a warehouse employee carrying out heavy manual handling at 28°C may be at greater risk than an office worker sitting at a desk in a well-ventilated 31°C environment.

A rigid legal limit could also create unintended consequences. Employers operating essential services, manufacturing facilities or healthcare environments may struggle to comply during extreme weather events. Also, speaking with the experience of someone who is intolerant to heat, individuals have different levels of tolerance for the heat.

Why People Want a Maximum Temperature

Campaigners and trade unions have long argued that the lack of a maximum limit leaves workers vulnerable. One of the primary risks associated with hot weather is heat stress. This occurs when the body is unable to regulate its internal temperature and can lead to symptoms such as fatigue, dizziness, headaches and confusion. In more serious cases, it can progress to heat exhaustion or heatstroke. Generally, excessive heat can lead to:

• Fatigue and reduced concentration

• Dehydration

• Heat exhaustion

• Heat stroke

• Increased risk of accidents and mistakes

• Reduced productivity

• Worsening of existing medical conditions

For workers performing physically demanding tasks the risks increase dramatically.

For office-based employees, productivity can decline significantly as indoor temperatures rise above comfortable levels. Workers often question why schools, public transport and workplaces can become uncomfortably hot without any clear legal trigger for action.

How do other countries deal with the heat?

Many point to countries such other European countries like Spain and Germany, where workplace temperature guidance is often more prescriptive, so can we learn anything from other countries?

Spain has some of the strictest workplace temperature laws in Europe, regulated by the National Institute for Hygiene and Safety at Work under Royal Decree 486/1997.

• Sedentary Work (e.g., Offices): The maximum legal temperature is 27°C.

• Light Physical Work: The maximum legal temperature is 25°C.

• Outdoor/Extreme Heat: Under Royal Decree-Law 4/2023, employers must modify or reduce working hours when Spain’s State Meteorological Agency (AEMET) issues red or orange heat alerts. If the situation poses an imminent risk, employees have the legal right to stop working and leave the premises.

Germany on the other hand does not have such a strict legally binding maximum temperature but employers are obligated to protect the health and safety of their staff. Guidelines are laid out in the ASR A3.5 (Technical Rules for Workplaces).

• Up to 26°C: This is the recommended maximum indoor temperature. If exceeded, employers should implement countermeasures (e.g., blinds, electric fans, or relaxing the dress code).

• Above 30°C: Employers must take effective countermeasures. This can include providing cold drinks, offering flexible working hours, or adjusting break times.

• Above 35°C: Rooms are considered unsuitable for standard work unless technical measures (like air conditioning) or personal protective equipment (like cooling vests) are provided.

France does not have a strict legal maximum temperature for the workplace. Instead, the French Labour Code requires employers to maintain a suitable temperature and guarantee employee health and safety.

Employer Requirements:

Under a decree that reinforces heat-related safety (Decree No. 2025-482), employers are required to:

• Adapt working conditions: Adjust work processes and schedules during intense heatwaves.

• Provide resources: Ensure constant access to cool drinking water and suitable personal protective equipment.

• Assess risks: Update the Document Unique d’Évaluation des Risques (DUERP) to include heatwave risks.

Recommended Thresholds:

While there is no legal limit, the French national institute for safety and health at work (INRS) advises that dangers increase when the ambient temperature exceeds 30° C for sedentary employees and 28° C for physical work. Furthermore, safety guidelines generally suggest that temperatures remain within 23° C to 26° C in the summer.

Employee Rights & Action:

If temperatures become dangerous, employees may exercise their "right of withdrawal" (Droit de Retrait) if they believe their working conditions present a serious and imminent danger to their life or health, allowing them to stop working without losing pay.

Some of the Middle East countries like Saudi Arabia, United Arab Emirates and Qatar have some of the strictest heat precautions for obvious reason and often enforce mandatory work bans. United Arab Emirates and Saudi Arabia both impose their own midday work bans whilst Qatar has introduced some of the world's most advanced heat stress regulations, combining temperature and humidity measurements to determine when work must stop.

Australia has no universal national maximum workplace temperature. Instead, employers must assess heat-related risks. In industries such as mining and construction, work may be suspended when temperatures or heat stress indices reach dangerous levels.

Some countries do legislate a maximum temperature for the workplace but many concentrate more on ensuring the risk is assessed and procedures and resources put in place to control and minimise that risk. This brings me on to look at what employers can do to minimise the effect of the heat on workers.

What Employers Should Be Doing Instead

Whether or not a legal maximum temperature is introduced, employers already have obligations to assess and control heat-related risks like any other hazard under HASAWA and other relevant legislation.

Practical measures include:

Improving Ventilation

Opening windows, using air conditioning, portable cooling equipment, mechanical ventilation systems and increasing airflow can significantly reduce heat stress.

Providing Cool Drinking Water

Easy access to cold drinking water is one of the simplest and most effective controls available.

Adjusting Working Hours

Where practical, physically demanding tasks can be scheduled during cooler parts of the day or introducing flexible working hours. Rotate physically demanding tasks and monitor vulnerable workers.

Relaxing Dress Codes

Allowing lighter clothing can improve comfort without compromising professionalism or safety.

Providing Additional Breaks

More frequent rest periods can help workers recover from heat exposure.

Relocate workstations

Re-positioning workstations away from direct sunlight or heat source to other shady parts of the workplace so no longer in hottest part of the office.

Conducting Heat Risk Assessments

Employers should consider vulnerable workers, including those with medical conditions, pregnant employees and older workers.

Outdoor Work During Heatwaves

For outdoor workers, employers should:

• Schedule strenuous work during cooler periods.

• Increase supervision.

• Provide shaded rest facilities.

• Monitor weather forecasts.

• Implement emergency procedures for heat-related illness.

Work may need to be modified, postponed or temporarily suspended where risks cannot be adequately controlled.

Is Climate Change Changing the Conversation?

The UK Met office says that since the 1980’s each decade has been warmer than the previous one. A decade ago, workplace temperatures exceeding 30°C were relatively unusual in much of the UK.

Today, temperatures above 35°C are no longer unthinkable, and climate projections suggest that extreme heat events will become more common. The world's 11 warmest years on record have all happened since 2015, according to the World Meteorological Organization (WMO).

The year 2024 was Earth's hottest ever recorded, with climate change mainly responsible for the high temperatures. Today, prolonged periods of extreme heat are becoming more common. Climate experts predict that heatwaves will become more frequent, higher peak temperatures will occur more regularly and businesses will need to adapt their workplaces to manage heat-related risks. Otherwise offices will become stifling, warehouses turn into ovens, and outdoor workers will prolonged exposure to direct sunlight.

What may once have been viewed as an occasional inconvenience is increasingly being recognised as a genuine occupational health issue. The TUC is also calling on ministers to make sure British workplaces are fit for a hotter climate. Public and private investment is needed to upgrade our buildings and infrastructure, so that they remain functional during heatwaves.

We must also continue with climate action so that we can prevent global heating become more extreme, with greater costs to our lives. 

So, Do We Need a Maximum Workplace Temperature?

There is a strong case for introducing clearer guidance, particularly as UK summers become hotter. However, a fixed legal maximum temperature may not be the best solution. Heat risk is influenced by far more than a single number on a thermometer.  Also the challenge will be finding a balance between protecting workers and recognising the practical realities faced by different industries.

A more effective approach could involve legally defined action levels. For example, as temperatures rise, employers could be required to implement additional control measures, conduct enhanced risk assessments and, where necessary, modify working practices. This would provide clearer protection for workers while recognising that different industries face different challenges.

Rather than introducing a strict maximum workplace temperature, some experts support a tiered approach.

For example:

Temperature Range	Suggested Employer Action
25°C - 27°C	Monitor conditions and increase ventilation
27°C - 30°C	Conduct heat risk assessments and introduce additional controls
Above 30°C	Implement enhanced control measures and consider reducing physical workloads
Extreme Heat Conditions	Review whether work can safely continue

This risk-based approach focuses on actual worker safety rather than relying solely on a thermometer reading.

Final Thoughts

The lack of a legal maximum workplace temperature in the UK continues to be a hot topic—quite literally. Yet the issue is more complex than simply choosing a number and writing it into law.

What matters most is not the temperature itself, but the risk it creates. While introducing a fixed upper temperature limit may seem attractive, workplace heat risks are influenced by far more than temperature alone. Humidity, workload, ventilation, and individual vulnerability all play important roles.

As the UK experiences hotter summers, employers who take proactive steps to manage heat exposure will not only comply with their legal responsibilities but also protect productivity, wellbeing and morale.

Whether through new legislation, updated guidance, or improved risk assessments, the conversation around workplace temperatures is unlikely to cool down anytime soon. It might be that rather than "What temperature is too hot to work?", employers should be asking: "What are we doing to ensure our employees can work safely and comfortably in hot conditions?"

That question may ultimately prove far more important than any number written into law.

Keith Mason

Pennine Partnership

Workplace temperature is just one of the many topics covered in the IOSH Managing Safely course which is still the default H &S course for managers, supervisors and anyone who is responsible for looking after other work colleagues’ safety.

Pennine Partnership have been delivering IOSH Managing Safely for over 15 years in an interesting and imaginative way. Please see our website for details of our next course in Burnley and other dates as well as our summer offer of buying 2 places on the same course date for £355.00 each instead of normal price of £395.00 visit www.penninepartnership.com