Published: July 2024
Reading time: 6 minutes
Suitable for: Business Owners, Managers, Supervisors and Employees
Topics: Heat Stress | Summer Safety | Welfare | Risk Assessment
At a glance
Main goal: Protect employees from heat-related illness during hot weather.
Who should be involved? Employers, managers, supervisors and employees.
Key action: Plan ahead, provide suitable welfare facilities and encourage employees to recognise the signs of heat stress.
Benefits: Improved employee wellbeing, reduced risk of illness and continued productivity during periods of hot weather.
Why this matters
Hot weather can have a significant impact on both employee wellbeing and business performance. As temperatures rise, employees may become tired more quickly, lose concentration and be more likely to make mistakes, increasing the risk of accidents and ill health.
For employees working outdoors or in hot indoor environments, excessive heat can lead to heat exhaustion or, in severe cases, heat stroke, which is a medical emergency.
By understanding the risks and planning ahead, employers can help keep their workforce safe, healthy and productive throughout the summer months.
What is heat stress?
Heat stress occurs when the body is unable to cool itself sufficiently to maintain a safe internal temperature.
Normally, the body cools itself by sweating. However, when temperatures are high, humidity increases or physical work is demanding, this natural cooling process may not be enough.
If left unmanaged, heat stress can develop into:
- Heat exhaustion
- Heat stroke
- Dehydration
- Muscle cramps
- Fatigue and reduced concentration
Heat stroke is a medical emergency and requires immediate treatment.
Who is most at risk?
Some employees are more vulnerable to heat-related illness than others.
This includes people who:
- Work outdoors in direct sunlight
- Carry out physically demanding work
- Wear heavy or non-breathable personal protective equipment (PPE)
- Work in hot environments such as kitchens, factories or plant rooms
- Have certain medical conditions or take medication that affects their ability to regulate body temperature
- Are pregnant
Employers should consider these factors when completing workplace risk assessments.
What are the warning signs?
Recognising the early signs of heat-related illness can prevent more serious conditions from developing.
Heat exhaustion
Common symptoms include:
- Heavy sweating
- Dizziness
- Headache
- Muscle cramps
- Feeling weak or tired
- Nausea
If someone is experiencing heat exhaustion, they should be moved to a cool place, encouraged to drink water and monitored closely.
Heat stroke
Heat stroke is a medical emergency.
Symptoms may include:
- Confusion or unusual behaviour.
- Loss of consciousness.
- Very high body temperature.
- Hot skin that may no longer be sweating.
- Seizures.
If you suspect someone has heat stroke, call 999 immediately.
What should employers do?
Employers should take reasonable steps to reduce the risks associated with hot weather.
Good practice includes:
- Completing a hot weather risk assessment
- Identifying employees most at risk
- Providing access to drinking water
- Encouraging regular hydration
- Providing shaded or cool rest areas
- Scheduling physically demanding work during cooler parts of the day where possible
- Allowing additional rest breaks
- Reviewing PPE requirements where appropriate
- Providing information on recognising heat-related illness
- Having appropriate emergency procedures in place
Planning ahead can significantly reduce the likelihood of heat-related incidents.
What should employees do?
Employees can also help protect themselves and their colleagues by:
- Drinking water regularly, even if they do not feel thirsty
- Wearing lightweight clothing where appropriate
- Using sunscreen and sun protection when working outdoors
- Taking regular breaks in shaded or cool areas
- Reporting symptoms of heat stress immediately
- Looking out for colleagues who may be showing signs of heat-related illness
Early action can prevent minor symptoms from becoming serious.
What does the law say?
Under the Health and Safety at Work etc. Act 1974, employers have a legal duty to protect the health, safety and welfare of their employees.
The Management of Health and Safety at Work Regulations 1999 require employers to assess workplace risks and implement suitable control measures, including those associated with extreme weather.
Certain serious work-related heat illnesses may also need to be reported under the Reporting of Injuries, Diseases and Dangerous Occurrences Regulations (RIDDOR).
Did you know?
Research has shown that workplace productivity begins to decline as temperatures rise above 24–26°C. At temperatures of around 33–34°C, a person carrying out moderate physical work may lose up to 50% of their work capacity, increasing fatigue and the likelihood of mistakes.
Related resources
Documents
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Need more help?
Preparing for hot weather is an important part of protecting your employees and maintaining a safe working environment. The Health & Safety Portal provides practical resources to help your business manage seasonal risks, including summer safety training, toolbox talks and guidance documents.
By planning ahead and taking simple preventative measures, you can reduce the risks associated with heat stress, support employee wellbeing and help ensure your business continues to operate safely throughout the summer.