Keeping Cool at Work: Tackling High Temperatures in the Workplace

Over the last few years, British summers have been getting hotter and hotter, making heat stress a real concern for workplaces that aren’t used to dealing with it.

July 2022 saw temperature climb above 40°C for the first time whilst more recently June 2026 saw a record high temperature for the month. Indeed, the number of days exceeding 30°C trebled between 2015 and 2024 compared to the 1961 to 1990 average. We’re clearly not talking about acute changes in weather here but an ongoing change to our climate.

Whether it’s a construction site baking in the sun, a busy factory floor without much ventilation, or even office staff struggling with poor airflow, managing heat risks is something every employer needs to take seriously.

Minimum and maximum workplace temperatures

Although guidance is offered for low temperatures, the Health and Safety Executive (HSE) does not set a specific legal upper temperature limit for workplaces.

There is therefore no maximum workplace temperature in UK law. However, working in hot conditions can lead to everything from mild dehydration and headaches to serious heat exhaustion or even heat stroke.

The Approved Code of Practice expands on the Regulations and states that the:

• “temperature of a workplace should normally be at least 16 degrees Celsius”
• “if work involves rigorous physical effort, the temperature should be at least 13 degrees Celsius”

These are guidelines rather than strict limits, meaning employers must always assess what is reasonable in the circumstances.

What is a “Reasonable” Workplace Temperature?

Regulation 7(1) of The Workplace (Health, Safety and Welfare) Regulations 1992 state that during working hours, the temperature in all workplaces inside buildings shall be reasonable.

There is no single legal temperature that applies to all workplaces. Instead, what is “reasonable” depends on factors such as:

• The type of work being carried out
• The physical demands of the role
• Ventilation and heat sources
• Clothing or personal protective equipment (PPE)
• Personal preference and individual differences

Consider “Thermal Comfort”

Employers should also not rely on temperature readings alone but an employee’s “thermal comfort”.

Thermal comfort is based on one’s own perception, meaning it differs from person to person. Factors affecting this include not just person preference but external environmental conditions, available ventilation, cooling or heating sources, the nature of the work and its physical demands and the clothing or PPE worn or required for the nature of work.

Legal Responsibilities for Employers

Although guidance is offered for low temperatures, the Health and Safety Executive (HSE) does not set a specific legal upper temperature limit for workplaces.

The HSE tells us that working in hot conditions can lead to everything from mild dehydration and headaches to serious heat exhaustion or even heat stroke.

It might sound like something that only happens abroad, but with UK temperatures climbing over 30°C more regularly, it’s very much a local issue now.

Legally, employers have a duty to keep staff safe:

• Health and Safety at Work Act 1974: Employers must ensure the health, safety, and welfare of employees, including from heat-related hazards.
• Management of Health and Safety at Work Regulations 1999: Risk assessments must cover any hazards, including excessive heat.
• Workplace (Health, Safety and Welfare) Regulations 1992: Workplaces must have a “reasonable” temperature and provide drinking water – simple, but often overlooked.

The Impact and Risk of Excessive Heat in the Workplace

Not everyone is equally affected by the heat. Outdoor workers, or those doing physically demanding jobs, obviously feel it more. But it’s worth remembering that older staff, pregnant women, or people with health conditions might be more vulnerable too.

The tricky part is that signs of heat stress can start subtly – feeling dizzy, a headache, or feeling sick – but these symptoms can quickly get worse if ignored. I always encourage managers and workers alike to be alert to these symptoms and not push through when feeling unwell.

Vulnerable Workers

Some employees may be more severely affected by hot weather, for example:

• Expectant mothers
• Older workers
• Those with underlying health conditions
• Workers under the effects of certain medications

If this applies to your organisation, your policies around managing workplace temperature may wish to allow for:

• Additional rest breaks
• Provision of additional equipment such as fans or air conditioning units

Employers should take additional care to identify and support vulnerable workers, on an individual basis.

Personal Protective Equipment (PPE)

The requirement for PPE in a task or role may further impact considerations around managing workplace temperatures.

PPE may reduce the body’s ability to evaporate sweat due to more layers or less wicking materials. It may also be more difficult to manage heat risks in that removal of PPE could expose the employee to hazards that the PPE is protecting them from.

In these situations, employees should make reasonable adjustments. Examples include:

• Allowing slower work rates
• Rotating staff out of a high temperature environment for frequently
• Allowing longer breaks for recovery
• Providing additional facilities for PPE to be dried so employees can change into fresh PPE more often or as required
• Considering adjusting work rotas to cooler periods of the day
• Reviewing your risk assessment to ascertain whether alternative (including automated) systems
• Evaluating where alternative or more modern PPE may offer a lighter alternative

It’s important that none of this jeopardises the protection that PPE offers, but opportunities may still exist when it comes to how your organisation’s use of PPE can help manage workplace temperatures.

Practical Steps to Reduce Heat Risks

From what I’ve seen, some practical steps can make a big difference.

1. Conduct a risk assessment to spot who’s most at risk and when.
2. Schedule tough jobs for cooler parts of the day
3. Offer plenty of water breaks and create shady or cooler rest areas.
4. Improve ventilation by opening windows or using fans.
5. Allow appropriate clothing to suit to temperature.
6. Train staff to spot early signs of heat stress.
7. Encourage open communication.

Ignoring heat risks isn’t just uncomfortable; it’s dangerous. When people are overheated, their concentration drops, accidents happen, and overall morale can take a hit. With hot summers likely to be the new normal, it makes sense to get ahead of the problem.

Further Reading

HSE: Working in hot environments https://www.hse.gov.uk/temperature/

British Safety Council: Heat stress in the workplace https://www.britsafe.org/safety-management/2025/this-weather-isn-t-much-fun-if-you-re-stuck-in-an-overheated-workplace-heatwave-advice-for-employers

ACAS: Temperature in the workplace https://www.acas.org.uk/extreme-temperatures-in-the-workplace

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