A growing frequency of extreme heat spells in recent years is placing increased emphasis on providing effective controls and safeguards in the workplace.

As temperatures rise across the UK, businesses are facing the challenge of maintaining a reasonable workplace temperature. Extreme heat poses a serious challenge to employee wellbeing and in turn business continuity.

To put this into context, on 19 July 2022 parts of the UK saw record summer temperatures with Coningsby in Lincolnshire reporting 40.3°C! This led to fire events in some regions and the first ever red travel warning in the UK. According to Met Office records, the UK has witnessed ten of its warmest years since 1884 in just the past two decades (2000 – 2020)1.

With continued exposure to extreme heat conditions in a workplace setting - in the office, at home and outside - risk events can escalate quickly, leading to heatstroke, delirium, organ damage and occasionally death. Other health issues emanating from extreme heat exposure include fatigue, difficulty concentrating, muscle cramps, nausea, heat stress, heat rash, dehydration and headache.

Reported evidence suggests a direct link between increases in temperature above comfortable levels and increases in accidents in the workplace2. As such, managing extreme heat in summer has become a pressing concern for employers in recent years.

Workplace temperature and the law

According to Regulation 7 of The Workplace (Health, Safety and Welfare) Regulations 1992 under the Health and Safety at Work Act 1974, employers are required to ensure that the temperature in the workplace is ‘reasonable’. While there are no stipulated temperature limits, the Health & Safety Executive (HSE) has an Approved Code of Practice (ACOP) with guidance for employers3.

The Approved Code of Practice recommends that temperatures not fall below 16°C for general work. The minimum temperature should be 13°C for work that requires rigorous physical effort. However, there is no recommended maximum temperature at the workplace4.

Increased calls to introduce maximum temperature limits are anticipated in response to the recurring hot summers. Last year, the GMB Union called on the government to set a maximum temperature of 25°C. NASUWT, the Teachers’ Union, has called for setting the standard maximum classroom temperature at 24°C5.

What should employers consider?

Employers have an overriding legal obligation to undertake a suitable assessment of health and safety risks to employees, of which temperature in the workplace is one.

Particular note should be taken of employees who find working in the heat more difficult than others, including where any pre-existing health condition(s) have a material impact, and consider what reasonable adjustments can be made in such circumstances.

The ACOP notes that if a reasonably comfortable temperature cannot be achieved through local cooling systems in the building in extremely hot weather, then fans and increased ventilation may be used.

Steps to manage heat-related risks at the workplace

With the Met Office officially declaring a heat wave in several regions in the UK6 at the time of writing, employers are recommend to follow a range of practical steps to minimise the impact of extreme heat in the workplace as part of health and safety obligations to their employees.

Here are some practical tips to avoid workplace challenges due to extreme heat:

  • Increase air circulation
    It is possible to bring the air temperature, velocity, and humidity to a comfortable level through adequate provision for natural ventilation and air conditioning in the work premises. If the office already has air conditioning, employers must ensure it operates optimally and implement upgradation where required. A mobile air conditioner is ideal in a temporary setting.

  • Keep it cool at work
    A sufficient number of thermometers should be provided to enable workers to determine the temperature in any workplace. To maintain a comfortable working temperature, electric fans and air conditioners should be operated as required and blinds / curtains / shades should be used to block out (or filter) sunlight coming into the room from windows.

    Any employees working outside should be provided with appropriate arrangements to stay hydrated and within safe working temperatures, including suitable shading protection, drinking water and sunscreen.

  • Highlight the importance of hydration
    Employers should encourage workers to stay hydrated by drinking plenty of water, with easy access to drinking water and water coolers.

  • Dress code
    Employers have the option to relax a uniform and/or office dress code requirements during hot weather periods to ensure workers are as comfortable as possible in higher temperatures. Those obligated to wear PPE uniforms can be given more frequent access to cooler areas to rest and take a break.

  • Commuting to work
    Employees’ attendance and being at work on time may be affected if the hot weather negatively impacts public transportation. To avoid travelling during the hot weather of the day, employees can check timetables in advance and communicate with their employer to discuss other options, such as working from home or staggering shift patterns.

  • Awareness and empathy
    Ensure that employees are able to recognise symptoms of heat stress through training and awareness and knows where to get help in the event of a problem. Where possible, give them the option to adjust their shift timings. Use signage to remind them to drink water and stay safe from the heat.

Closing thoughts...

Wherever there is clear evidence of health risks at work, employers should respond proactively to manage (ideally eliminate) these risks. The Health & Safety Executive advises employers to undertake a thermal comfort risk assessment in the workplace. To this end, employers have the option to engage the services of a risk management expert to provide practical solutions to safeguard employees during extended periods of extreme heat.

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To speak with a member of our friendly risk management team about any of the content in this article or how we can help you with any of your risk management requirements, call 0800 138 7538.


The sole purpose of this article is to provide guidance on the issues covered. This article is not intended to give legal advice, and, accordingly, it should not be relied upon. It should not be regarded as a comprehensive statement of the law and/or market practice in this area. We make no claims as to the completeness or accuracy of the information contained herein or in the links which were live at the date of publication. You should not act upon (or should refrain from acting upon) information in this publication without first seeking specific legal and/or specialist advice. Arthur J. Gallagher Insurance Brokers Limited accepts no liability for any inaccuracy, omission or mistake in this publication, nor will we be responsible for any loss which may be suffered as a result of any person relying on the information contained herein.