Industry Guides

How to Keep Staff Cool, Safe, and Compliant During Heatwaves

15th July 2026

The UK’s relationship with hot weather has changed. What used to be a welcome novelty - a few sticky days in July before the clouds returned - now regularly tips into something more serious. Heatwaves are on the rise, longer-lasting, and far less predictable.

For office workers, that might mean a sluggish afternoon. For those on a construction site, in a warehouse, or on a delivery round, it can be dangerous.

If you manage people in physical or outdoor roles, summer heat belongs on your risk assessment. This guide covers the risks, your legal responsibilities, and how to keep your team safe and working at their best when temperatures climb.

Why Heatwaves Are a Workplace Risk

Heat doesn’t just make people uncomfortable; it impairs their ability to work safely.
Heat stress occurs when the body can no longer cool itself efficiently. If left unaddressed, discomfort can progress to heat exhaustion and, in the worst cases, to heatstroke, which is a medical emergency. Workers in physical roles, those wearing heavy or multi-layered PPE, and anyone working outdoors or in airless spaces are at significantly higher risk.

Dehydration compounds the problem quickly. Even mild dehydration reduces concentration, slows reaction time, and makes errors more likely. In industries where mistakes have physical consequences, this risk adds up.

Fatigue is the third factor. Physical output drops, coordination suffers, and workers push through when they should stop - often because no clear signal tells them otherwise.

The industries most exposed are also among the most physically unforgiving: construction, manufacturing, warehousing, logistics, and hospitality. In each, the demands of physical exertion, limited ventilation, and required PPE create conditions for heat-related illness during a sustained heatwave.

Your Legal Responsibilities

There is no maximum workplace temperature written into UK law. It’s a point that sometimes confuses employers into thinking heat is a grey area. But it isn’t.

Under the Health and Safety at Work Act 1974, employers have a general duty to ensure the health, safety, and welfare of their employees, as far as is reasonably practicable. Under the Workplace (Health, Safety and Welfare) Regulations 1992, that duty includes maintaining a reasonable working temperature and providing suitable rest facilities.

The HSE is clear that while no exact upper temperature limit exists, employers must carry out a sufficient risk assessment, and thermal comfort is part of that. When temperatures rise, that risk assessment needs to reflect the changed conditions.

This means:

Keeping an eye on working conditions during hot weather
Revising risk assessments to treat heat as a seasonal hazard
Making reasonable adjustments to working practices
Ensuring PPE is compliant and thermally manageable

If an employee suffers a heat-related illness and your risk assessment doesn’t mention thermal hazards, the consequences for your business are significant. Prevention is considerably cheaper.

Choosing The Right Summer Workwear

What your team wears is one of the most direct levers you have on comfort and safety in the heat. Alongside discomfort, the wrong summer workwear may also work against the body’s ability to keep cool.

Fabric

Cotton is a reliable summer staple; it’s breathable, skin-friendly, and highly suitable for embroidered branding. For more active roles, moisture-wicking fabrics are worth the investment. These draw sweat away from the skin and allow it to evaporate, keeping workers drier through a shift. Avoid pure polyester and nylon in peak summer; both trap warmth and hold moisture against the skin.

Colour

Lighter colours reflect heat. A white or pale grey polo on a sun-exposed site is measurably cooler than a navy equivalent. Where branding allows, lighter summer options are worth exploring. Do remind outdoor workers that white clothing offers minimal UV protection (around 5-7 UPF), so sun cream still applies.

Fit and sleeves

Looser cuts allow air to circulate, for example, in trousers and base layers worn under PPE. Where the environment permits, t-shirts, polos, and open collars should be the default.

For more details on fabrics and fits, see our guide on what to wear to work in hot weather.

Don’t Compromise on PPE

Hard hats, high-visibility clothing, safety footwear, gloves, and site-specific protective equipment remain legally required where hazards exist, regardless of the temperature. A heatwave doesn’t change the risk that PPE is designed to protect against.

What it does change is the conversation with your suppliers. Summer-specific options have improved considerably. Vented hard hats allow airflow without compromising impact protection. Lightweight, open-weave high-vis vests provide the same visibility and keep workers cooler. Breathable safety footwear also exists across most standard safety ratings.

The right question to put to your PPE supplier is whether a compliant summer version is available. In most cases, it does.

Adjust Working Practices

Workwear and PPE are only part of the answer. The bigger impact comes from how work is organised during a heatwave.

Shift timing

The hottest part of the day in the UK typically falls between 11am and 3pm. Where operationally possible, shift strenuous work to earlier or later in the day for outdoor-heavy roles.

Breaks

Regular rest breaks in the heat are not a productivity loss; they’re a productivity preservation measure. Workers who push through heat make more mistakes and are more likely to need time off.

Shade, cooling, and water

Shaded rest places and portable fans are basic control measures, not perks. Position them close to the heaviest work areas to make them easy to use. Water should be available throughout the shift, but remember, a hydration policy only works if water is where the work is.

Quick checklist: Heatwave readiness

Before the next period of hot weather arrives, work through this checklist with your H&S and operations teams.

Workwear and PPE

Is lightweight summer workwear available for all roles?
Has PPE been checked for summer-appropriate alternatives?
Are all options compliant and certified?

Site and environment

Are shaded areas confirmed on all sites?
Has ventilation in enclosed spaces been checked?
Is drinking water available at all work areas?

Working practices

Are shift patterns reviewed?
Have break schedules been updated?
Have changes been communicated to the team?
Is sun cream available for outdoor workers?

Risk assessments and policy

Are risk assessments updated to include thermal hazards?
Are supervisors clear on what adjustments they can make on-site?
Is there a reporting mechanism in place for workers feeling unwell?

Training and awareness

Has a toolbox talk or briefing on heat illness been delivered?
Are signs of heat exhaustion and heatstroke covered?
Has a first aider been confirmed on each site or team?

Getting Summer Right, Responsibly

Heatwaves are no longer brief disruptions. For employers with staff in physical roles, a heatwave is a recurring seasonal hazard - and one that sits within your duty of care.

The steps involved are neither complicated nor expensive. Reviewing your workwear, refreshing risk assessments, adjusting working patterns, and briefing your team all make improvements to safety and comfort.

The businesses that get hot weather right are the ones that prepare before forecasts change, not during or after. If you need help reviewing your summer workwear provision, our team can help.

Browse our summer workwear range.

Here at MyWorkwear, we have been proud suppliers of personalised workwear since 1976.

To see how we can provide the perfect workwear for your team to keep them looking professional and performing at their best, please click the button below.