Hot weather at work – why employers should prepare before temperatures rise

What you need to know about workplace temperature, and the steps that can help protect both employees and your business.

Warm weather may be welcome outside working hours, but it can quickly become a challenge in the workplace. A stuffy office, overheated warehouse or uncomfortable outdoor working environment can affect concentration, productivity and wellbeing, and it often leaves managers fielding the same question – when is it too hot to work?

For UK employers, this is no longer something to deal with only when a heatwave arrives. Hotter summers and more frequent periods of extreme heat mean temperature should be treated like any other foreseeable workplace risk, in that they are assessed, planned for and managed consistently.

Working alongside Alliotts, Reality HR helps businesses take a practical, people-first approach to issues like this. Here is what you need to know about workplace temperature, and the steps that can help protect both employees and your business.

Is there a legal maximum workplace temperature?

In short, no. There is currently no legal maximum temperature for workplaces in the UK. The reason is that working environments vary so widely, for example, what is reasonable in an air-conditioned office may be very different from what is achievable in a bakery, kitchen, factory or outdoor setting. You should therefore assess the risks in your own workplace rather than rely on one fixed number.

The Workplace (Health, Safety and Welfare) Regulations 1992 require employers to provide a “reasonable” indoor temperature. Guidance suggests a minimum of 16°C, or 13°C where the work involves significant physical effort, but there is no equivalent upper limit.

As an employer, you still have wider health and safety duties, including assessing risks and putting controls in place where heat could affect employees. The HSE’s heat stress checklist can be useful for identifying where action may be needed.

There has also been continued debate about whether the UK should introduce a statutory maximum, with the TUC previously calling for an upper limit of 30°C, or 27°C for physically demanding work. Whether or not the law changes, if you take a proactive and well-documented approach you will be in a much stronger position.

Practical steps employers can take before a heatwave

A last-minute response to hot weather may get your business through a hot week, but it rarely gives managers or employees enough clarity. A better approach is to review your hot weather arrangements before summer starts, agree what will happen when temperatures rise, and make sure managers know how to apply the plan fairly.

1. Include heat in your risk assessment

Including heat in your risk assessment would involve identifying the areas roles and working patterns most likely to be affected by the hot weather. This might include south-facing workspaces, kitchens, warehouses, vehicles, outdoor roles or employees required to wear PPE. Once the risk is understood, decide what rules are needed and when they will be triggered.

2. Build in sensible flexibility

Temporary changes to hours, shift patterns, break times or home working can all help, but they are easier to manage when the parameters are already clear. If employees are working from home during hot weather, check that this is actually a safer and more comfortable option for them, rather than assuming it will be.

3. Consider practical workplace adjustments

Fans and portable cooling units can be useful, but longer-term measures may be more effective. Better ventilation, reflective window film, blinds, shaded break areas, improved insulation or air conditioning can all reduce the impact of high temperatures on your working environment and ensure employees are comfortable enough to work. Small changes, such as moving desks away from direct sunlight or relaxing uniform rules, can also make a difference.

4. Review dress codes and PPE requirements

As we mention above, where a formal dress code is in place, consider whether it can be relaxed during hot weather without affecting safety or professionalism. If PPE is required, you should look at whether lighter, breathable or cooling alternatives are available and suitable for the role.

5. Make sure employees take water and rest breaks

It sounds obvious, but access to water and the ability to take breaks should be built into hot weather planning, particularly for employees doing physical work, wearing PPE or working outdoors.

Remember that heat affects employees differently

Not everyone experiences high temperatures in the same way. Pregnant employees, menopausal employees, disabled employees and those with certain medical conditions may be more affected by heat and may need individual adjustments. Managers should be encouraged to listen to concerns and include them in the risk assessment process.

Neurodivergent employees may also experience additional sensory discomfort during hot weather, particularly where changes to temperature, clothing, noise from fans or crowded spaces make the working environment harder to manage. Managers should be prepared to consider reasonable adjustments on a case-by-case basis.

Also, poor sleep, fatigue and increased stress during prolonged hot weather can affect performance and behaviour at work. Regular check-ins with your people help managers identify issues early and show employees that concerns will be taken seriously.

Communicate the plan clearly

Employees should know what support is available, who to speak to if they are struggling, and what changes may be introduced during periods of hot weather. Communicating this before summer, rather than during a heatwave, makes the process feel planned and fair.

It is also sensible to keep records, such as monitoring indoor temperatures where concerns are raised, documenting adjustments and keeping risk assessments up to date can all help demonstrate that your business has taken reasonable steps if a complaint or claim arises later.

When should employers seek HR advice?

It may be helpful to seek expert HR advice to review your existing policies and get support putting clear processes in place.

We recommend you seek advice if you receive complaints from employees or if employees have specific health or disability-related concerns. Also, if you’re making changes that affect working hours, uniform rules or workplace facilities. Getting guidance early can prevent small issues becoming formal disputes.

FAQs

Is there a temperature UK staff can legally refuse to work in?

No. There is no legal maximum workplace temperature in the UK, only a legal minimum – 16°C, or 13°C where the work involves significant physical effort. As an employer, you must keep temperatures “reasonable” and carry out a thorough risk assessment wherever heat could pose a hazard.

Can employees be required to keep working during a heatwave?

There is no automatic right for employees to stop work once it gets hot, but your duty of care as an employer still applies, so it’s important you try to make reasonable adjustments where possible.

If conditions are genuinely unsafe and no reasonable steps have been taken to address them, this could expose your business to a health and safety or personal injury claim.

Do we need a written policy for managing hot weather?

A hot weather policy isn’t a specific legal requirement, but it is strongly recommended. A written policy gives managers and employees clarity, ensures a consistent approach, and provides evidence that reasonable steps were taken if a complaint or claim is later raised.

What if an employee says their home isn’t cool enough to work from?

Any concerns from your employees about working in hot temperatures should be taken seriously, as a duty of care applies wherever someone is working – including home. A brief check-in or self-assessment can help establish whether home working is genuinely suitable that day, or whether another arrangement is needed. Listen to any concerns your employees may have and try to work with them to come to a solution.

How often should our approach be reviewed?

Ideally you can review your hot weather policy and processes once per year, before the summer months, so it reflects current guidance, any changes to the workplace, and lessons learned from the previous year.

How we can help

We work alongside Alliotts to support businesses with practical HR advice, including reviewing existing policies and helping businesses put clear processes in place before issues arise.

If you would like help reviewing your approach to workplace temperature, please get in touch with our team at info@realityhr.co.uk or call 01256 328 328.

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