The Ultimate Guide to Avoiding Heat Stress in the Workplace (2025)

blog 07 Jul 2023

When the temperature rises, so does the risk of heat stress – especially for workers in outdoor or high-temperature environments. Whether you're managing a team on-site or working in a warehouse, occupational heat stress is a real and rising concern. This guide covers everything you need to know to protect your team, from early warning signs to preventative strategies.

Quick navigation

What is heat stress?
Symptoms: What to watch for
Who’s most at risk?
How to prevent heat stress
What the law says
Smart equipment choices
What to do in an emergency
Final tips

What is heat stress and why does it matter?

Heat stress happens when the body can’t cool itself fast enough - due to high temps, strenuous work, and heat-trapping PPE. If left unchecked, it can quickly progress to heat exhaustion or heatstroke.

Did you know? The number of UK heat-related workplace incidents rose 28% from 2020 to 2024 (HSE data).

Symptoms: what to watch out for

Recognise symptoms early to prevent escalation:

Early signs

Heavy sweating
Headache or nausea
Muscle cramps
Weakness or fatigue

Severe signs
Confusion or irritability
Vomiting
Fainting
Seizures or collapse

Tip: Train teams to monitor themselves and each other during hot spells.

Heat exhaustion and heat stroke explained

Who’s most at risk of heat stress?

Anyone working in heat is at risk of heat stress. Some environments and jobs increase the risk:

Construction workers exposed to sun + physical labour
Manufacturing staff near ovens or furnaces
Warehouse teams in poorly ventilated areas
Utility crews working long hours outdoors
People with underlying conditions (e.g. heart disease)

Some people, such as those with existing health conditions, may be more vulnerable.

Heat stress control measures

Hydration & Breaks

Drink cool water every 15–20 minutes
Avoid caffeine or energy drinks
Encourage frequent, shaded breaks

PPE & Clothing
Use lightweight, breathable PPE
Avoid gear that traps heat (e.g. foul weather PPE in summer)
Remove PPE during breaks in safe zones

Shift Management

Rotate workers to limit prolonged exposure
Reduce physically intense tasks during peak heat hours

Ventilation & Cooling

Use fans, air conditioning, or evaporative coolers
Provide temporary shelters or shaded areas

Examples of methods to keep cool in the workplace

Heat stress regulations in the workplace

UK regulations require employers to protect workers from known risks - including heat.

Key Regulations:

Workplace (Health, Safety and Welfare) Regulations 1992

Requires indoor temperatures to be “reasonable” (usually 16°C+)

Health and Safety at Work Act 1974

Mandates risk assessments and control measures

Employers must:

Conduct a heat stress risk assessment
Provide training and PPE
Adapt working conditions during high heat

Smart equipment for effective heat management

Hiring the right gear can make a big difference:

• Temporary cooling solutions - From portable fans to evaporative coolers, the right equipment can make all the difference. Portable cooling fans circulates the air in enclosed spaces, whilst evaporative coolers reduces the temp by up to 10°C

Shelters and shaded rest stations reduce sun exposure during breaks
Hydration stations provide constant access to chilled water and welfare units offer cooled areas for rest and recovery

What to do in an emergency

If someone shows signs of heat stress:

Move them to a shaded or cool space
Give water to drink (small sips, not gulping)
Remove excess clothing/PPE
Seek medical help if symptoms worsen or do not improve quickly

Final tips and takeaways

Regular training and awareness are key to prevention
Monitor weather forecasts and plan around extreme heat, adjusting shifts accordingly
Build a team culture of looking out for one another on-site

Check and maintain all cooling equipment regularly.