Written by Sam Dow | 28th July 2025
Most people look forward to the sunshine, long evenings and pub gardens that come with a UK heatwave. But the downside of the warm weather usually shows up during working hours, when trying to focus in a hot, stuffy environment becomes a challenge and can leave employees feeling tired, irritable and less productive.
As a line manager or team lead, you may find yourself being asked if it is ever too hot to work or what to do when the workplace feels like a sauna. With warmer days becoming more common, it’s important to understand what the law actually says and doesn’t say about workplace temperature, and what practical steps you can take to keep your team well, safe and able to do their job.
What does the law say about workplace temperature
Workplace temperature is both a legal responsibility and a wellbeing priority, but unfortunately there is no legal maximum workplace temperature in the UK.
According to the Health and Safety Executive (HSE), this is because every workplace is different. In many indoor workplaces, hot environments can be caused by work conditions and processes such as in manufacturing plants, boiler rooms, bakeries or catering kitchens.
The Workplace (Health, Safety and Welfare) Regulations 1992 require employers to maintain a “reasonable” temperature inside buildings, but what counts as reasonable can vary. While there is a legal minimum temperature requirement of 16°C (or 13°C for physical work), there is no upper limit on workplace temperatures specified in law.
Beyond this, the Health and Safety at Work Act 1974 places a broader duty of care on employers to protect the health, safety and welfare of their employees. The Management of Health and Safety at Work Regulations 1999 also require employers to carry out risk assessments, including for heat and temperature-related risks.
Failure to respond appropriately to excessive heat in the workplace could lead to enforcement action by the HSE, health-related claims, or a noticeable drop in productivity.
Recognising temperature related issues
Knowing when it’s getting too hot isn’t just about checking the room temperature. As a line manager, you need to be alert to signs that employees are struggling with the heat. These can include physical symptoms like headaches, fatigue, dehydration, nausea or dizziness. You might also notice changes in behaviour, such as irritability or difficulty concentrating.
When the body is no longer able to cool down and the temperature becomes dangerously high, this is a sign of heat stroke. Heat-related illness can escalate quickly, so it’s important that you and your line manager colleagues are aware of the signs to quickly take action, as this can turn into a medical emergency.
From a performance angle, heat can lead to more mistakes, slower working speeds and even an increase in absences. If your team’s performance starts to dip during hot spells, or people seem noticeably uncomfortable, that’s a good indication that conditions need to be addressed.
It’s also important to pay extra attention to vulnerable groups, including pregnant employees, those experiencing menopause, and those with health conditions that could be worsened by heat. Any incidents or concerns raised should be recorded as part of your health and safety procedures, and risk assessments may need to be updated accordingly.
Practical steps line managers can take during hot weather
There are plenty of small, immediate changes that can make a difference to your employees’ comfort and productivity during warm weather.
- Offer flexible working
On abnormally hot days, you might allow staff to start earlier and finish early to avoid working in the hottest part of the day. You could also allow remote working if it will be more comfortable for employees to work at home. It will also prevent them from travelling in hot weather.
- Encourage hydration
It goes without saying that drinking water is essential in hot weather, especially if employees have more labour-intensive jobs like in warehouses or industrial settings. In addition to making water more easily accessible for employees, such as providing a machine, or bottled water, you should allow more frequent breaks to help employees cool down.
- Relax the dress code
Where it is safe to do so, you may wish to relax the workplace dress code so employees can wear what makes them comfortable. For example, swapping shirts and jackets for polo shirts or t-shirts.
Safety clothing and equipment are often very warm. For those working outside or doing heavy jobs, you could supply PPE designed for hot weather, such as breathable fabrics like cotton and linen, or cooling shirts and gloves – which are designed to promote airflow and help regulate body temperature. Making sure there are good supplies of suncream, and sun hats is also a good idea.
If uniforms are required, you may want to look into lighter materials, that still looks smart and maintains the business’s image.
- Make workstation and space adjustments
Some employees might be working close to direct sunlight, heat sources or in spaces where there is less ventilation. If you can, make adjustments to where they work such as providing portable air conditioning units or fans, or move them away from windows.
You may want to cover windows with reflective film that can help keep the heat out or provide shaded rest areas for outdoor workers.
Longer term, it may be worth discussing bigger changes with your employer. This could involve installing air conditioning, improving insulation or rethinking your office layout to improve airflow. The key is to show you’re taking the issue seriously and doing what you can to reduce discomfort.
Employee communication
Clear, proactive communication goes a long way in managing temperature-related concerns. Make sure your team knows what measures are in place, who to speak to if they’re uncomfortable, and what to expect during hot weather. Keep people updated if you’re making changes, and be open to feedback ideas.
Regularly monitoring temperatures and sharing this information helps build trust and shows that you’re taking the issue seriously.
Monitoring and documentation
Keep a log of indoor temperatures during warm periods, especially if your team has raised concerns. Update risk assessments to reflect the impact of heat on different roles and review these regularly.
If someone reports a health issue related to temperature, or if you make adjustments in response to complaints, make sure everything is documented. This helps protect both employees and the business in the event of future claims or investigations.
Policies around heat management should be reviewed annually, ideally before summer begins, to ensure they reflect current guidance, working practices and any changes to your workplace setup.
When to escalate or seek advice
If heat is affecting your team’s health, safety or ability to perform their roles you may need to seek advice on any changes to policies or working conditions.
Formal complaints about temperature, especially if raised repeatedly, should be taken seriously. You may need expert input to assess whether legal obligations are being met and what further steps are required. If you’re unsure what you can and can’t do, such as adjusting uniform rules, introducing shift changes or updating your workplace facilities, it’s always best to get advice.
We can help you develop a sensible, legally compliant approach to managing workplace temperature, including a policy that is tailored to your business,
If you have any questions, please get in touch with our team at info@realityhr.co.uk or call 01256 328 428.