As the UK experiences another period of exceptionally hot weather, many employers are once again thinking about managing heat stress in the workplace. While heatwaves often bring welcome sunshine, they can also pose significant workplace health and safety challenges, particularly for employees working outdoors, performing physically demanding tasks, or working in buildings that become excessively warm.
Unlike some other countries, there are no legal maximum temperatures for working in the UK. However, this does not mean employers can ignore the impact of extreme heat. Employers continue to owe a duty of care to their workforce and must take reasonable steps to protect employees from risks associated with high temperatures.
For employers and HR professionals, managing heat stress in the workplace is not simply a matter of employee comfort. It is an important aspect of workplace health and safety that can affect productivity, sickness absence, employee wellbeing and legal compliance.
The Current Heatwave and Why It Matters
Periods of prolonged hot weather can affect virtually every workplace, regardless of sector. Office environments may become uncomfortable where ventilation is poor, while employees working in warehouses, factories, kitchens or outdoor settings may face significantly higher risks due to physical exertion and prolonged exposure to heat.
Heat can affect concentration, increase fatigue and reduce productivity. Employees who become overheated may experience dizziness, headaches, dehydration or heat exhaustion, all of which can increase the likelihood of workplace accidents and mistakes.
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Certain employees may also be more vulnerable than others. Older workers, pregnant employees, individuals with underlying medical conditions and those taking particular medications may be at greater risk during periods of extreme heat.
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As climate patterns continue to change, heatwaves are becoming more frequent across the UK, making effective heat management an increasingly important consideration for employers.
Is There a Legal Temperature to Work in the UK?
One of the most common questions employers ask during periods of hot weather is whether there is a legal maximum workplace temperature.
The simple answer is no. There are currently no legal temperature limits in the UK that require employers to stop work once a particular temperature is reached.
Instead, the Workplace (Health, Safety and Welfare) Regulations 1992 require employers to provide a reasonable indoor working temperature, while the Health and Safety at Work etc. Act 1974 places a broader duty on employers to ensure, so far as is reasonably practicable, the health, safety and welfare of employees.
Government guidance and the Health and Safety Executive (HSE) make it clear that employers should assess workplace risks associated with heat and take appropriate measures to reduce those risks. The focus is therefore on risk management rather than compliance with a fixed temperature limit.
Simply because there is no legal maximum temperature does not mean employers can continue operating as normal where employees face significant heat-related risks.
Why Managing Heat Stress in the Workplace Matters
Heat stress occurs when the body is unable to cool itself effectively, causing core body temperature to rise. If left unmanaged, heat stress can lead to dehydration, heat exhaustion and, in more serious cases, heatstroke, which is a medical emergency.
For employers, the consequences extend beyond employee health. Heat-related fatigue can impair judgement, slow reaction times and increase the likelihood of workplace accidents. This is particularly important in safety-critical industries such as construction, manufacturing, logistics and transport.
Heat can also contribute to higher levels of sickness absence, lower productivity and reduced employee morale. When employees feel that employers are failing to take reasonable steps to protect their well-being, employee relations issues may also arise.
From a legal perspective, employers who fail to manage foreseeable risks associated with excessive heat could face enforcement action from the Health and Safety Executive, personal injury claims, or regulatory investigations following workplace incidents.
Employer Obligations During Hot Weather
Employers should begin by conducting suitable and sufficient risk assessments to determine whether excessive heat poses a foreseeable risk to employees. This assessment should consider both environmental conditions and the nature of the work being undertaken.
The risks associated with working in the heat will vary depending on factors such as physical activity, humidity, ventilation, direct sunlight, protective clothing and the duration of exposure.
Employers also have a responsibility to ensure employees receive appropriate information and guidance regarding heat-related risks. Managers should understand the signs of heat exhaustion and know how to respond if an employee becomes unwell.
Where particular groups of employees face increased vulnerability, additional support or adjustments may be required. Individual circumstances should always be considered as part of the wider risk assessment process.
Practical Steps Employers Can Take
Managing heat stress in the workplace often involves a combination of practical adjustments and sensible workforce planning.
Where possible, employers should improve ventilation by using air conditioning, fans or natural airflow to reduce indoor temperatures. Employees should also have access to an adequate supply of cool drinking water and be encouraged to remain hydrated throughout the working day.
Work patterns may also require adjustment during periods of extreme heat. Employers could consider scheduling physically demanding work during cooler parts of the day, increasing the frequency of rest breaks or rotating duties to reduce prolonged exposure to high temperatures.
Flexible working arrangements may also assist in some workplaces. Earlier start times, hybrid working or temporary adjustments to working hours may help employees avoid travelling or working during the hottest periods of the day where operationally feasible.
Dress codes should also be reviewed. Where safety permits, employers may wish to temporarily relax clothing requirements to allow employees to wear lighter, more breathable clothing while maintaining appropriate professional standards.
Communication is equally important. Employees should understand the symptoms of heat-related illness and feel comfortable raising concerns if workplace conditions become unsafe or uncomfortable.
Special Considerations for Managing Heat Stress in the Workplace
Employees working outdoors often face the greatest risks during hot weather. Construction workers, delivery drivers, agricultural workers and others exposed to direct sunlight for extended periods require particular attention.
Employers should consider providing shaded rest areas, encouraging regular hydration, allowing additional breaks and ensuring appropriate personal protective equipment does not unnecessarily increase heat exposure.
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Some indoor workplaces may also experience elevated temperatures due to machinery, poor ventilation or manufacturing processes. Employers should not assume that indoor work automatically presents lower risks.
Regular monitoring of workplace conditions during periods of extreme heat can help employers identify problems before they lead to illness or disruption.
Managing Heat Stress in the Workplace: Our Final Thoughts
As periods of hot weather become increasingly common across the UK, managing heat stress in the workplace is becoming an essential part of effective health and safety management. While there are no legal temperatures to work in the UK, employers remain under a clear legal duty to protect employees from foreseeable risks associated with excessive heat.
For employers and HR professionals, this means taking a proactive approach to risk assessments, supporting employees working in the heat and implementing practical measures that safeguard health and wellbeing.
Organisations that prepare for hot weather, communicate clearly with employees and adapt working practices where appropriate are likely to reduce sickness absence, maintain productivity and demonstrate their commitment to employee welfare.
Ultimately, managing heat stress in the workplace is not simply about complying with health and safety obligations. It is about creating a safe and supportive working environment that enables employees to perform effectively, even during periods of extreme weather.
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