This summer has made history: the UK has officially recorded eight days of temperatures at or above 34°C, a small yet significant jump from the previous record of seven. With the Met Office warning that very warm weather looks set to continue, heat at work is no longer a short-lived inconvenience that employees and employers can wait out.
For many employers, the same questions come up every time hot weather hits. What are we actually required to do? Is it too hot for my team? Can employees refuse to work if they think it’s too hot?
This guide will answer all these questions and more, helping you and your team stay comfortable and maintain positive relationships when working in the heat.
Is There a Legal Maximum Working Temperature in the UK?
Currently, there is no legal maximum workplace temperature in the UK.
The Health and Safety Executive (HSE) has explained that no meaningful upper limit has previously been imposed because in many indoor workplaces, high temperatures are caused by the work activity itself, not just the weather outside.
A bakery or a foundry, for example, will always run hot, meaning that a fixed temperature ceiling could make normal operations much more difficult.
Instead, the Workplace (Health, Safety and Welfare) Regulations 1992 require that indoor workplaces are maintained at a “reasonable” temperature during working hours. The regulations don’t define what “reasonable” looks like, leaving it to the employer to determine based on the nature of the work and the environment.
However, the absence of a maximum temperature figure doesn’t give employers a free pass. If anything, it places a more active duty on employers: rather than waiting for a thermometer to hit a fixed threshold, they need to make a judgement call and act on it.
What Are Employers’ Legal Obligations When It’s Hot?
So if there’s no maximum temperature, what does the law actually require?
The starting point is the Health and Safety at Work etc. Act 1974, the main piece of legislation covering occupational health and safety in Great Britain. This places a duty on employers to ensure that, so far as is reasonably practicable, employees and others affected by the work are not exposed to risks to their health or safety.
The Management of Health and Safety at Work Regulations 1999 go further, requiring employers to carry out a risk assessment that identifies potential risks, considers the likelihood of harm, and sets out action to eliminate or control those hazards (with heat being considered a hazard).
When it comes to what you should actually do, the HSE recommends that employers consider a range of practical measures during periods of high temperature. These include:
- Local cooling – fans, air conditioning, or opening windows where possible.
- Adjusted dress codes -relaxing uniform or dress code requirements to allow cooler clothing (while still ensuring that PPE is used when required).
- Access to water -providing cool, fresh drinking water that’s readily and freely accessible throughout the working day.
- Flexible working patterns -moving the most physically demanding tasks to the cooler parts of the day, such as early morning.
- More frequent breaks -increasing both the frequency and duration of rest periods.
- Moving work -where possible, enabling employees to work in cooler areas of the building.
- Staff rotation -rotating people between tasks so that no one is continuously exposed to the hottest conditions.
The key principle running through all of this is reasonableness. Naturally, you’re not expected to air-condition every corner of every workplace overnight. But you are expected to think actively about the risks of working in the heat and take proportionate steps to manage them.
For help making sure your approach to heat forms part of a coherent, well-documented HR and health and safety strategy, our HR strategy support can help you take stock of where you are and where you need to be.
A Note on Vulnerable Employees
It’s easy, when thinking about heat in the workplace, to focus on the general workforce and overlook the fact that some employees face significantly greater risks than others.
Under the Equality Act 2010, employers have a duty to make reasonable adjustments for disabled employees where an aspect of the workplace puts them at a disadvantage compared to non-disabled colleagues. In a heatwave, this could be very relevant.
Several groups may be particularly vulnerable to heat-related health risks:
- Older workers, whose ability to regulate body temperature naturally declines with age.
- Pregnant employees, where rising core body temperature reduces blood flow to the uterus, affecting the supply of oxygen and nutrients to the baby.
- Employees with certain disabilities or health conditions, including those whose medication affects how their body responds to heat.
- Employees experiencing menopause, for whom high temperatures can significantly worsen symptoms such as hot flushes, palpitations, and dizziness.
When you’re putting heat management measures in place, consider whether they work equally well for everyone. A relaxed dress code, for example, might not be enough for an employee whose medication affects their heat tolerance.
Often, the most effective first step is simply starting a conversation with your employees. Asking someone how they’re getting on with working in the heat costs nothing, and it can prevent a difficult situation from developing further.
At What Temperature Can You Refuse to Work in the UK?
Employees do not have an automatic legal right to stop working simply because they feel it’s too hot.
Under the Employment Rights Act 1996, an employee can only legitimately refuse to work if they reasonably believe that the conditions pose an immediate and serious risk to their health and safety.
However, employees who raise genuine concerns about heat are protected. Employers cannot take disciplinary action against someone for flagging a legitimate health and safety concern.
For employers, the best way to avoid any of this arising is to act before it gets to that point. If you can see that members of your team are struggling, don’t wait for a formal complaint. A proactive response is almost always better than a reactive one.
If a specific situation arises that you’re not sure how to handle, our ad hoc HR support is there for exactly that kind of thing.
Is the Law on Working in The Heat About to Change?
The HSE is progressing a wider review of its Approved Code of Practice for the Workplace (Health, Safety and Welfare) Regulations 1992, with a public consultation expected later this year.
The stated aim is to ensure the guidance is “fit for purpose for a modern workplace”, and it’s widely anticipated that this review may result in clearer thresholds for recommended maximum working temperatures being set out in official guidance for the first time.
The pressure to act has been building. Unions, including Unison and the TUC itself, have reiterated calls for a specific legal maximum temperature of 30°C for indoor work, or 27°C for those doing strenuous work. There has also been a Parliamentary petition calling for a legally binding maximum temperature of 25°C that has attracted thousands of signatures.
Joining the conversation is the British Safety Council, which has called for statutory guidance that establishes practical trigger temperatures and proportionate control measures, rather than leaving employers to interpret the law without a clear benchmark.
Working in The Heat: Your Checklist
Before the next stretch of hot weather arrives, here’s a sensible starting point for making sure your approach to heat in your workplace is in good shape:
- Risk assessment – carry out or review a heat risk assessment covering all areas of your workplace and all roles.
- Vulnerable employees – identify anyone who may be more at risk and consider what additional or tailored support they might need.
- Communication – make sure your team knows what to do if they’re struggling and who to speak to; don’t assume people will just ask.
- Dress code – review your policy to allow appropriate adjustments during hot weather, and communicate any temporary changes clearly.
- Water – ensure cool drinking water is freely available and accessible throughout the working day in all areas.
- Flexibility – consider flexible start times, home working options, or task rotation on days of extreme heat, where operationally possible.
- Manager confidence – check that your line managers feel equipped to handle heat-related concerns calmly and proportionately, without either dismissing them or escalating unnecessarily.
This isn’t an exhaustive compliance exercise, but these checks can help you and your team get through a hot summer without unnecessary difficulty.
Need a Hand Managing Heat in Your Workplace?
This summer has made clear that working in the heat is no longer something UK employers can treat as an occasional inconvenience. It’s becoming a regular part of workforce management, and the legal expectations around it may be tightening.
If you’d like support reviewing your approach to risk assessments or handling a specific situation related to the heat, we’re here to help.
Get in touch via our contact page or find out more about how our HR strategy support can help you build an approach that works for your business and your people.