Working in High Temperatures: Protecting Your Workforce During Hot Weather

With temperatures climbing across much of the UK, conversations about working in high temperatures are becoming increasingly common across construction sites, warehouses, manufacturing facilities, offices, schools, and outdoor environments.

And while there is no maximum legal working temperature in the UK, employers still have very clear legal responsibilities.

Heat is a workplace hazard.

Just like noise, asbestos, work at height, or machinery, heat must be properly assessed, managed, and controlled.

This is becoming an increasingly important challenge for employers, supervisors, and health and safety professionals, particularly as the UK continues to experience more frequent periods of extreme weather.

What Does the Law Say About Working in Hot Temperatures?

Under the:

• Health and Safety at Work etc. Act 1974
• Management of Health and Safety at Work Regulations 1999
• Workplace (Health, Safety and Welfare) Regulations
• CDM Regulations (for construction)

employers have a legal duty to protect workers from risks to their health and safety, including heat-related risks.

The HSE makes it clear:

There may not be a legal maximum temperature, but workers are entitled to an environment where risks are properly controlled.

That means employers must:

• Assess risks
• Introduce control measures
• Consult workers
• Review conditions during extreme weather
• Protect vulnerable workers

Why Heat Is a Serious Workplace Hazard

Many people still underestimate the dangers of heat exposure at work.

Heat doesn’t just make people uncomfortable, it can significantly affect:

• Concentration
• Decision-making
• Reaction times
• Physical performance
• Fatigue levels
• Hydration
• Mental wellbeing

In high-risk industries like construction, transport, engineering, manufacturing, warehousing, and agriculture, this can dramatically increase the likelihood of accidents and mistakes.

What Is Heat Stress?

According to HSE guidance, heat stress occurs when the body can no longer properly regulate its internal temperature.

This can happen because of:

• High air temperatures
• Humidity
• Direct sunlight
• Heavy physical work
• Poor ventilation
• PPE restricting airflow
• Lack of hydration
• Long exposure times

Common Symptoms of Heat Stress

Workers and managers should recognise early warning signs, including:

• Excessive sweating
• Headaches
• Fatigue
• Muscle cramps
• Dizziness
• Nausea
• Confusion
• Fainting
• Difficulty concentrating

Severe heat stress can develop into heat exhaustion or even heat stroke, which can become life-threatening.

Outdoor Workers Face Increased Risks

Those working outdoors face additional hazards from:

• Direct sunlight
• UV exposure
• Dehydration
• Hot machinery and surfaces
• Reduced concentration and fatigue

This is particularly relevant within:

• Construction
• Roofing
• Scaffolding
• Groundworks
• Utilities
• Highways
• Agriculture
• Landscaping

Hot weather can also affect the safe use of:

• Machinery
• Vehicles
• Tools
• PPE
• Respiratory equipment

PPE and Heat Stress

One of the biggest overlooked issues is the impact PPE can have during hot weather.

Many forms of PPE reduce the body’s ability to cool itself, including:

• Respiratory protection
• Flame-resistant clothing
• Coveralls
• High-visibility clothing
• Gloves
• Harnesses

This creates a difficult balance between protection from workplace hazards and protection from heat.

Good risk management may involve:

• Slower work rates
• More frequent breaks
• Rotating workers
• Additional hydration
• Alternative PPE
• Rescheduling tasks

Practical Ways Employers Can Reduce Heat Risks

The HSE recommends a range of practical controls, including:

Environmental Controls

• Fans and ventilation
• Air conditioning
• Shading
• Cooling systems
• Moving workstations away from heat sources

Administrative Controls

• Earlier start times
• Flexible working
• Increased rest breaks
• Job rotation
• Rescheduling heavy work

Hydration Controls

• Providing cool drinking water
• Encouraging regular hydration
• Avoiding reliance on thirst alone

PPE Management

• Reviewing whether all PPE is necessary
• Introducing lighter PPE where suitable
• Providing facilities to dry or change PPE

Risk Assessment Is the Key

One of the strongest messages from the HSE guidance is simple:

Heat must be risk assessed.

That means employers should assess:

• Air temperature
• Humidity
• Air movement
• Work intensity
• Exposure duration
• PPE requirements
• Vulnerable individuals
• Outdoor exposure
• Rest arrangements
• Welfare facilities

This is where competent health and safety leadership becomes critical.

Developing Safety Leaders Who Can Manage Real-World Risks

At Acadame, this is exactly why qualifications like the:

• NEBOSH National General Certificate
• NEBOSH Certificate in Fire Safety

remain so valuable.

These qualifications help develop professionals who can:

• Carry out meaningful risk assessments
• Identify workplace hazards
• Understand legal responsibilities
• Apply practical controls
• Influence management decisions
• Lead workplace safety culture

Because health and safety isn’t just about policies, it’s about recognising evolving risks and making sensible, proportionate decisions in real working environments.

Heat Risk Is Only Going to Become More Important

Periods of extreme heat are becoming more frequent across the UK.

Forward-thinking organisations are already recognising that managing temperature-related risks is now part of modern health and safety leadership.

The businesses that adapt early will protect:

• Their people
• Their productivity
• Their reputation
• Their legal compliance

Upcoming NEBOSH Courses at Acadame

If you’re looking to strengthen your health and safety knowledge or develop stronger leadership skills within your organisation, our upcoming courses include:

📅 NEBOSH National General Certificate
📅 NEBOSH Certificate in Fire Safety

Delivered by a Gold NEBOSH Learning Partner and one of the UK’s few triple UKAS-accredited training providers.

Final Thoughts

Heat-related illness can escalate quickly, particularly in physically demanding environments like construction, warehousing, manufacturing, and outdoor work. Recognising the signs of heat exhaustion or heat stroke early, and knowing how to respond, can make a critical difference.

That’s why managing hot weather risks isn’t just about prevention. It’s also about ensuring workers and supervisors are prepared to act if something goes wrong.

Strong health and safety leadership, effective risk assessment, and properly trained first aiders all play a vital role in protecting people during periods of extreme heat.

At Acadame, we help organisations develop competent safety professionals and confident workplace responders through qualifications such as the:

• NEBOSH National General Certificate
• NEBOSH Certificate in Fire Safety
• Emergency First Aid at Work
• First Aid at Work

Because when temperatures rise, preparation matters.