Why the UK Doesn’t Have a Maximum Workplace Temperature – And Why That’s the Right Approach

During every spell of hot weather, such as we are experiencing right now, calls inevitably grow for the UK to introduce a legal maximum workplace temperature. At first glance, it sounds like a simple solution. If it’s too hot, work should stop.

However, when considered in the context of the wide variety of workplaces across the UK that I visit, a single legal temperature limit is neither practical nor likely to improve worker safety.

The current legal framework places the emphasis where it belongs: on assessing and managing risk.

One Temperature Does Not Fit Every Workplace

The UK workforce operates in an enormous range of environments.

 A warehouse operative may work in a large building where temperatures fluctuate significantly throughout the day. Construction workers are exposed to changing weather conditions, while foundry workers, commercial kitchens, glass manufacturers and laundries routinely work in environments where elevated temperatures are part of the normal process.

Equally, many office workers may experience discomfort in a poorly ventilated building during a heatwave, despite temperatures being considerably lower than those experienced in industrial settings.

Introducing a single legal temperature at which work must stop would fail to recognise these very different circumstances.

The Law Already Requires Employers to Manage Heat

The Health and Safety at Work etc. Act 1974 requires employers to protect the health, safety and welfare of their employees, so far as is reasonably practicable.

Supporting regulations, including the Management of Health and Safety at Work Regulations 1999 and the Workplace (Health, Safety and Welfare) Regulations 1992, require employers to assess workplace risks and provide a working environment that is reasonable.

Importantly, the legislation does not define a maximum temperature because temperature alone does not determine risk.

The same air temperature may present little difficulty for one worker while creating significant risks for another, depending on factors such as:

• Physical workload.
• Humidity.
• Radiant heat from machinery or processes.
• Air movement and ventilation.
• Clothing and personal protective equipment.
• Length of exposure.
• Individual health and medical conditions.
• Acclimatisation to working conditions.

These factors combine to create heat stress, which cannot be measured simply by looking at a thermometer.

Risk Assessment Remains the Most Effective Approach

Rather than focusing on a single temperature threshold, employers should assess whether workers are likely to experience harmful levels of heat stress and implement proportionate controls.

In many situations, relatively straightforward measures can significantly reduce risk without disrupting operations.

Examples include:

• Providing cool drinking water and encouraging regular hydration.
• Increasing rest breaks during periods of extreme heat.
• Rescheduling physically demanding tasks to cooler parts of the day where practicable.
• Improving ventilation or air movement.
• Providing shaded rest areas for outdoor workers.
• Reviewing the suitability of PPE where alternatives are available.
• Monitoring workers for signs of heat-related illness.
• Giving additional consideration to vulnerable workers, including new starters, pregnant workers and those with underlying medical conditions.

The controls adopted should always reflect the specific activities being undertaken rather than an arbitrary temperature.

A Dynamic Risk

Heat should also be viewed as a dynamic risk.

Conditions may change throughout the day as temperatures rise, humidity increases or workloads change. Effective organisations recognise these changing conditions and adapt accordingly, rather than relying on a risk assessment completed weeks or months earlier.

Managers and supervisors should be empowered to modify work arrangements where necessary, based on actual conditions rather than waiting for predefined temperature limits to be reached.

Balancing Worker Protection with Operational Reality

Some have argued that introducing a legal maximum temperature would provide greater clarity for employers.

While understandable, such an approach could unintentionally create new problems. A fixed legal limit may encourage organisations to treat compliance as a simple numerical exercise, rather than properly assessing the actual risks present.

Conversely, workplaces operating safely at temperatures above that limit through effective engineering controls, ventilation, hydration and work-rest regimes could face unnecessary disruption, while other workplaces presenting significant heat stress below the limit might mistakenly be considered safe.

A risk-based approach encourages employers to consider the whole working environment rather than a single measurement.

Five Questions Every EHS Manager Should Ask During a Heatwave

Periods of hot weather can develop quickly, and the level of risk may change throughout the working day. Rather than relying solely on a seasonal risk assessment, EHS managers should ask five simple questions whenever temperatures begin to rise:

1. Have workplace conditions changed since the risk assessment was completed?

Risk assessments should be dynamic. A sudden increase in temperature, changes in humidity, additional radiant heat from equipment or altered work patterns may all require existing control measures to be reviewed.

2. Who is most at risk?

Not everyone will be affected in the same way. Consider workers carrying out physically demanding tasks, those required to wear extensive PPE, new starters who may not yet be acclimatised, pregnant workers, older employees and anyone with underlying health conditions that may increase their susceptibility to heat stress.

3. Are the current control measures still adequate?

Simple interventions can often make a significant difference. Consider whether additional drinking water is readily available, whether rest breaks should be increased, if work can be rescheduled to cooler periods of the day, or whether ventilation and air movement can be improved.

4. Are supervisors equipped to recognise the early signs of heat stress?

Supervisors are often the first to notice when someone is becoming affected by heat. They should understand the early symptoms, such as dizziness, excessive sweating, fatigue, headaches, confusion or muscle cramps, and be confident to intervene before a situation escalates into a medical emergency.

5. Could today’s controls become tomorrow’s normal practice?

With hotter summers becoming more frequent, organisations should consider whether temporary measures introduced during periods of extreme heat should become part of routine seasonal planning. Reviewing what worked well—and what didn’t—can help improve resilience for future years.

Looking Ahead

Climate projections suggest that periods of extreme heat are likely to become more frequent across the UK. For many organisations, this means heat risk management can no longer be viewed as an occasional summer issue but should become part of routine health and safety planning.

Whether work takes place in an office, warehouse, manufacturing plant or outdoors, employers should ensure that heat-related risks are considered within their existing risk assessment processes and that suitable controls are implemented whenever conditions require them.

The absence of a legal maximum workplace temperature should not be interpreted as an absence of legal responsibility. Instead, it reflects a regulatory approach that recognises the diversity of UK workplaces and places the emphasis on managing real risks rather than complying with an arbitrary number.

Ultimately, effective health and safety management has always been about understanding risk, applying proportionate controls and protecting people. Heat is no different.