Hot Weather at Work: Employer Responsibilities During Heatwaves and HSE Guidance for 2026

As temperatures continue to rise across the UK, employers are being reminded of their legal responsibilities to protect workers from the risks associated with hot weather and workplace heat stress.  If you have questions and are (or want to be) a Safety~net Competent Person Scheme member, please contact us for further information and guidance.

The Health and Safety Executive (HSE) has recently updated its guidance for employers, highlighting the importance of managing workplace temperatures and taking practical steps to prevent heat-related illness during periods of extreme weather.

While UK law does not set a maximum workplace temperature, employers still have a duty of care to ensure working conditions are safe, healthy and do not place employees at risk.

What Are an Employer’s Responsibilities During Hot Weather?

Many employers are surprised to learn that there is no legal maximum temperature for workplaces in the UK.

However, under health and safety legislation, employers must assess workplace risks and implement suitable control measures where high temperatures could affect employee health, safety or wellbeing.

This applies to:

• Offices
• Warehouses
• Manufacturing facilities
• Construction sites
• Outdoor workplaces
• Agricultural environments
• Logistics and transport operations

As part of their workplace risk assessment, employers should identify situations where excessive heat could lead to illness, fatigue, reduced concentration or increased accident rates.

What Is Heat Stress at Work?

Heat stress occurs when the body’s natural cooling mechanisms are unable to maintain a safe internal temperature.

When employees become too hot, they can develop heat-related illnesses ranging from mild discomfort through to serious medical emergencies such as heat exhaustion and heat stroke.

Common Signs of Heat Stress

Employees and supervisors should be aware of symptoms including:

• Excessive sweating
• Dizziness
• Headaches
• Muscle cramps
• Fatigue
• Nausea
• Reduced concentration
• Confusion
• Rapid heartbeat

Recognising these symptoms early can help prevent more serious health consequences.

Why Heat Stress Is Becoming a Growing Workplace Safety Issue

Heatwaves are becoming more frequent and intense across the UK.

According to climate projections, extreme weather events are expected to increase in both frequency and severity over the coming decades. This means workplace heat exposure is no longer an occasional summer concern but an emerging long-term occupational health and safety challenge.

High temperatures can:

• Reduce productivity
• Increase worker fatigue
• Impair decision-making
• Increase accident rates
• Contribute to dehydration
• Exacerbate existing medical conditions

For employers, failing to manage these risks can result in increased sickness absence, reduced operational performance and potential enforcement action where risks have not been adequately controlled.

Which Workers Are Most at Risk During a Heatwave?

Certain employees are particularly vulnerable to hot weather conditions.

Higher-risk groups include:

• Outdoor workers
• Construction workers
• Road and rail maintenance teams
• Agricultural workers
• Manufacturing employees
• Warehouse operatives
• Workers wearing PPE
• Pregnant employees
• Older workers
• Employees with underlying health conditions
• New starters who have not yet acclimatised

Risk assessments should specifically consider these groups and any additional controls required.

HSE Guidance: How Employers Can Reduce Heat Stress Risks

The HSE recommends a range of practical measures to help employers manage workplace temperatures and protect their workforce during hot weather.

1. Review Work Schedules

Where possible:

• Move physically demanding tasks to cooler parts of the day
• Avoid unnecessary manual handling during peak temperatures
• Introduce task rotation
• Consider flexible working hours

2. Provide Access to Drinking Water

Dehydration significantly increases the risk of heat stress.

Employers should ensure:

• Cool drinking water is readily available
• Workers are encouraged to drink regularly
• Remote workers have suitable hydration arrangements

3. Improve Ventilation and Airflow

For indoor workplaces, employers should consider:

• Increasing natural ventilation
• Opening windows and doors where safe
• Using fans appropriately
• Improving air circulation
• Introducing cooling systems where necessary

4. Increase Rest Breaks

Additional rest periods can help workers recover from heat exposure.

Employers should provide:

• More frequent breaks
• Cool recovery areas
• Shaded outdoor rest locations

5. Review Personal Protective Equipment (PPE)

PPE can increase heat stress by limiting the body’s ability to cool itself.

Employers should:

• Review whether alternative PPE options are available
• Monitor workers undertaking strenuous tasks
• Ensure regular breaks are provided

6. Train Employees to Recognise Heat-Related Illness

Workers should understand:

• Signs and symptoms of heat stress
• Emergency procedures
• Reporting requirements
• The importance of hydration and rest

Outdoor Working in Hot Weather

Outdoor workers face additional risks due to direct sun exposure and prolonged periods in high temperatures.

Employers should consider:

• Providing shaded work areas
• Adjusting work schedules
• Monitoring weather forecasts
• Providing sun protection measures
• Increasing supervision during heatwaves

Planning ahead can significantly reduce the likelihood of heat-related illness and lost working time.

Is There a Legal Maximum Workplace Temperature in the UK?

This remains one of the most frequently asked workplace health and safety questions.

Currently, there is no legal maximum workplace temperature in UK legislation.

However, employers are still required to ensure workplace temperatures are reasonable and do not create health and safety risks.

Trade unions and occupational health organisations continue to campaign for a maximum legal workplace temperature, particularly as climate change increases the frequency of extreme heat events.

Until any legislative changes are introduced, employers must rely on robust risk assessments and proportionate control measures to demonstrate compliance.

Heatwave Workplace Safety: Key Actions for Employers

As temperatures continue to rise, employers should take a proactive approach to managing heat-related risks.

Key actions include:

✓ Reviewing workplace risk assessments

✓ Identifying vulnerable workers

✓ Providing access to water and rest facilities

✓ Improving ventilation and cooling

✓ Adjusting work schedules where necessary

✓ Training staff to recognise heat stress symptoms

By implementing these measures, organisations can improve employee wellbeing, maintain productivity and demonstrate compliance with their health and safety obligations.

Need Help Reviewing Your Workplace Risk Assessments?

Heat stress is increasingly becoming a significant workplace health and safety issue across the UK.

If your organisation has not reviewed its hot weather arrangements recently, now is an ideal opportunity to assess existing controls and ensure employees remain protected during periods of extreme heat.

A proactive approach today can help prevent incidents, reduce sickness absence and support legal compliance throughout the summer months.