Working in warm weather is becoming increasingly common for UK workers as global temperatures continue to rise. The UK may not be commonly associated with blue skies and soaring temperatures, but the last few years have indicated that it may become more frequent when summer rolls around. With recent workplace health and safety failures fervently highlighted by Health and Safety Executive (HSE) prosecutions, the last thing employers want is to subject their workers to intense heat without proper regard for their well-being.
Heatwaves and extended periods of no rain can make working in hot weather extremely difficult for workers across the UK. Heat stress, specifically, is becoming a growing health risk for workers, and employers must take note of this. According to recent data from the UK Health Security Agency (UKHSA), the summer of 2023 (the eighth warmest on record) saw 2,295 deaths associated with five intense heat periods. The same agency and the Met Office issued an amber heat health alert across most of the country in September, during which there was reportedly a 552% rise in visits to the NHS England page on heat exhaustion and heatstroke.
Therefore, it’s clear that this issue needs addressing, as summer 2024 – already witnessing a yellow heat health alert issued for England this June – looks set to be another full of scorching temperatures. So, let’s take the opportunity to understand the common risk factors associated with hot environments, from food manufacturing factories and warehouses to hospitals and even offices, and understand the factors that can exacerbate underlying health symptoms.
Understanding Heat Stress in the Workplace
Heat stress occurs when someone’s body cannot adequately control its internal temperature. This can then lead to a number of heat-related illnesses and, from a workplace perspective, increase the risk of accidents and injuries, while lapses in concentration and greater fatigue can have a knock-on effect on productivity.
When temperatures are high, employers and employees must understand the risks of heat stress and take appropriate measures to prevent them.
Common Risk Factors for Heat Stress
Certain workplaces present higher risks for workers depending on the nature of the work involved and the average indoor and outdoor temperatures workers would be exposed to. Some workplaces are outdoors, like agricultural work, roadworks, construction, forestry, and traffic force workers, meaning many hours are spent without sufficient air conditioning and ventilation, while indoor facilities like wholesale bread bakeries, logistics warehouses, and manufacturing plants protect them from scorching sunlight, but can pose excessive temperature risks.
As a general guide, these are the most common risk factors for heat stress, heat stroke or sunstroke:
- Air temperature, wind and humidity
- Sun radiation
- Radiant heat sources like ovens and furnaces
- Emissions from machinery and equipment
- Limited air movement indoors
- Physical exertion
- Lack of acclimatisation
- Use of bulky or non-breathable protective clothing and equipment
Heat Stress and Heat Stroke Symptoms
Heat stress refers to the overall heat load on the body, which – when symptoms are mild – may make workers uncomfortable and may affect their concentration and performance. However, when exacerbated, the heat can be dangerous and lead to symptoms such as:
- Nausea
- Vomiting
- Excessive fatigue
- Dizziness
- Muscle cramps and aches
- Physical weakness
- Headaches and migraines
Heat stroke (or sunstroke) occurs when someone’s body temperature is abnormally elevated well beyond its core temperature of 37°C. This is a true medical emergency that can often prove fatal if not treated promptly.
These types of symptoms can make heat stress worse and increase the chances of workers contracting heat stroke:
- Dehydration
- Lack of breaks or rest periods
- Poor physical fitness
- Certain medical conditions (e.g., heart disease, diabetes)
- Some medications
- Pregnancy
- Advanced age
- Alcohol consumption or drug use
Recognising the Signs of Heat Stress and Heatstroke
It’s essential for both employers and employees to be able to identify the signs of heat-related illnesses. These can range from mild to severe and include:
- High body temperatures (above 39°C) and fevers
- Hot, red, dry, itchy or damp skin with rashes
- Difficulty breathing
- Heavy sweating
- Dizziness and confusion
- Nausea and vomiting
- Muscle spasms – usually in the abdomen, arms or legs
Legal Requirements and HSE Guidelines
Contrary to popular belief, there is no specific legal maximum working temperature in the UK. Employers, however, have a duty of care to ensure their employees’ health, safety, and well-being under the Health and Safety at Work Act 1974.
This includes ensuring that the temperature in indoor workplaces is reasonable and that appropriate measures are taken to protect workers from heat stress.
Additionally, the Workplace (Health, Safety and Welfare) Regulations 1992 require employers to provide a reasonable temperature in the workplace.
HSE guidance on suitable workplace temperatures advises the following:
- For sedentary work (e.g., offices and desk work): at least 16°C
- For physical work: at least 13°C
While these are not maximum temperatures, they serve as a starting point for employers to assess and manage heat-related risks in the workplace.
How to Manage and Prevent Heat Stress
A risk assessment will be the ideal starting point for employers to identify how at-risk their employees are of heat stress.
This process should include identifying the most common heat stress hazards and determining who within the team is most likely to suffer symptoms and how. Evaluate the risks and decide on the most appropriate precautions to keep them safe while working in high temperatures.
Based on the risk assessment findings, employers should implement appropriate control measures. These may include:
- Installing air conditioning systems
- Increasing air ventilation
- Providing fans and dehumidifiers
- Scheduling work during cooler parts of the day
- Increasing the frequency and length of rest breaks
- Providing cool drinking water and rest areas
- Implementing a buddy system for workers to monitor each other for symptoms
- Ensuring PPE is temperature-appropriate
- Encouraging easy reporting of symptoms
- Inspecting and maintaining equipment for adequate temperature control
- Implementing additional precautions for vulnerable workers or those with underlying health concerns
Over time, findings should be recorded and any policies for working in extreme temperatures must be updated accordingly. Good integrated facilities management will help your company to take into account the environmental elements of an office that could be improved and managed, feeding into enhanced wellbeing.
Next Steps for Health and Safety Officers
Employers across the UK must realise that extreme heat is going to become more common in the UK, particularly as climate change continues to impact global temperatures. Therefore, it’s prudent to make heat stress management a core part of your workplace health and safety policies, especially if your team is exposed to high temperatures when the weather is cooler.
Understanding the common risk factors, symptoms, signs, and HSE recommendations for heat management in the workplace will give you a firm foundation on which to build. Following this guidance will ensure you identify the most appropriate control measures and policies to protect your workers from heat-related illnesses, while maintaining a safe and productive work environment.
Health and Safety Officers play a crucial role in this process, developing the right plans and measures to ensure environmental condition monitoring and also the training of staff on proper heat stress symptom recognition and reporting. Remember that prevention is key when it comes to heat stress and heatstroke, and it’s better to safeguard your team before they develop symptoms rather than expose them to high temperatures and deal with health and safety issues as they happen. The more proactive you are in making workplaces safe in all heat conditions, the safer they will be all year round and the less likely your workers are to succumb to serious heat-related problems.
