The wrong kit in summer is a hazard. Heat stress sends workers to hospital. The right summer workwear keeps your team cool, safe, and productive through even the hottest shifts.
Good news: breathable PPE exists that meets every UK safety standard. You don't have to choose between protection and comfort. You just need to know what to look for — and that's exactly what this guide covers.
We go garment by garment. Fabric tech in plain English. UK legal duties clearly explained. And a dedicated section on women's summer workwear — something you won't find in most guides.
What is heat stress — and why does it matter?
Heat stress happens when your body can't cool itself down. Your core temperature keeps rising. Your body's cooling system starts to fail.
It's not just discomfort. The HSE lists the symptoms as muscle cramps, heat rash, severe thirst, dizziness, and fainting. Left untreated, it becomes heat exhaustion. Then heatstroke — which can be fatal.
PPE makes the risk worse. Heavy or poorly fitting garments stop your body sweating properly. That's why your choice of summer workwear matters so much.
Outdoor workers carry the highest risk. Construction, highways, rail, utilities, landscaping — anyone doing hard physical work in the sun. But workers in poorly ventilated indoor spaces are at risk too.
What the law says about working in the heat
There is no maximum legal working temperature in the UK. The HSE confirms this clearly. No single number works across every workplace.
But heat is still a legal hazard. Under the Management of Health and Safety at Work Regulations, you must assess the risks and act. Under the Workplace (Health, Safety and Welfare) Regulations, you must keep the temperature at a reasonable level.
The HSE guidance on managing hot conditions says to:
- Reschedule heavy outdoor tasks to cooler parts of the day
- Give workers more frequent rest breaks in shaded areas
- Provide free, cold drinking water at all times
- Encourage workers to remove PPE during rest — it helps shed heat fast
- Review your risk assessment every summer season
You can relax your dress code in hot weather. PPE stays on whenever it's needed. Lighter, breathable PPE is the answer — not removing protection.
What fabrics actually keep you cool?
Not all fabrics are equal in the heat. Here's what to look for — in plain terms.
Fabric weight (gsm)
Gsm means grams per square metre. It tells you how heavy the fabric is. Lower number, lighter garment.
For summer workwear, look for fabrics in the 120–180gsm range. At that weight, you get real protection without baking. Heavy cotton shirts at 250gsm or above trap heat within an hour on a hot site.
Moisture-wicking
Moisture-wicking fabrics pull sweat away from your skin. They spread it across the garment's outer surface. It evaporates fast. You stay drier — and cooler.
Standard cotton holds sweat against your body. That raises your core temperature instead of lowering it. On a long summer shift, the difference is significant.
Mesh panels
Mesh panels let air flow straight to your skin. You'll find them under the arms, across the back, and along side seams. They matter most in still, humid conditions where there's no breeze.
Stretch fabrics
Stretch fabric moves with your body. Less pulling means less friction. Less friction means less heat at skin level. For physical jobs — bending, kneeling, climbing — stretch is worth having.
All protective clothing sold in the UK must meet BS EN ISO 13688:2022. That's the base standard for fit, skin safety, and durability after washing. It applies on top of specific standards like ISO 20471 for hi-vis.
UV protection: what UPF means and why it matters
If your workers are outdoors, UV protection isn't optional. The HSE is direct about it. Long-term sun exposure causes skin cancer. That risk is highest for people working outside every day.
UPF stands for Ultraviolet Protection Factor. It measures how much UV a garment blocks. UPF 40+ blocks up to 97.5% of UV rays. That's the rating to look for in outdoor summer workwear.
The key standard is EN 13758-2. This tests the whole finished garment — not just a fabric sample. Seams, stitching, and construction all count. A garment can only carry a UPF 40+ claim if the complete item passes the test.
Long sleeves give better UV coverage than short sleeves. That's the trade-off. In very hot conditions, a UPF 40+ long-sleeve polo gives more sun protection but traps more heat than a t-shirt. Pick based on your site's UV exposure and temperature.
Read our full explainer: UV Protection Workwear Explained: What Is UPF and Why It Matters for UK Outdoor Workers.
Browse our UV Workwear collection for rated options.
Hi-vis t-shirts and polo shirts for summer
Most outdoor workers need hi-vis. The question is which class — and which garment type fits the job.
ISO 20471 hi-vis classes in plain English
ISO 20471 is the UK standard for high-visibility clothing. It has three classes based on fluorescent and reflective material coverage.
- Class 1 — lowest coverage. Fine for low-traffic environments.
- Class 2 — used on most UK construction and utilities sites.
- Class 3 — full coverage. Required near live traffic at speed. Think highways and rail.
A short-sleeve t-shirt can reach Class 1 or 2. A long-sleeve polo adds arm coverage and can reach Class 2 or 3. Check your site's hi-vis requirement before you buy.
What to look for in a summer hi-vis top
- Fabric weight of 140–160gsm for the best balance of comfort and durability
- Moisture-wicking polyester — not cotton
- Mesh ventilation zones under the arms or across the back
- UPF 40+ if your workers are outdoors for long periods
Leo Workwear's Coolviz Plus fabric is built for this. The polo shirt below is ISO 20471 Class 2 rated and carries the moisture-wicking, lightweight construction your workers need through a full summer shift.
Leo Wringcliff Long Sleeve Hi Vis Polo Shirt ISO 20471 Class 2
The EcoViz t-shirt from Leo Workwear uses recycled polyester. It's Class 1 rated and one of the lightest options we stock. Good for lower-risk environments or layered builds.
Leo Forda Hi-Vis T-Shirt EcoViz Class 1 Orange or Yellow Navy
Browse our full range: Hi Vis Polos, Hi Vis T-Shirts, and Breathable Hi Vis.
For Class 3 requirements, see our Class 3 Hi Vis collection. For one-piece options, see Hi Vis Coveralls & Overalls.
Need help picking the right top? Read: Best Breathable Hi-Vis T-Shirts for Summer Work: UK Buyer's Guide.
Summer work trousers: what to look for
Trousers are the most overlooked part of summer kit. They shouldn't be. The wrong trousers cause fatigue, overheating, and restricted movement on hot days.
Stretch trousers vs cargo trousers
Stretch trousers move with you. They're built for physical jobs — kneeling, crouching, climbing. The fabric doesn't pull or bind. Less effort means less body heat generated.
Cargo trousers give you pockets. Useful for trades that carry tools — electricians, groundworkers, maintenance crews. More pockets means less need for a heavy tool belt. Less weight carried means less heat retained.
Both work well in summer. The right choice depends on your job.
What to avoid
Heavy denim is the worst choice for summer. It holds heat, restricts movement, and dries slowly when wet. Drop it from your summer uniform.
For hi-vis sites, look for ISO 20471-rated trousers. These combine the hi-vis stripe requirement with lightweight, breathable fabrics.
Leo Workwear Hawkridge Hi Vis Stretch Jogger style Trousers Orange Grey
Leo Workwear Hi Vis Stretch Trousers Class 1 EcoViz Orange Navy
Leo Workwear Bideford Hi Vis Cargo Trousers Yellow Grey
See our full Summer Work Trousers collection.
For a full product comparison, read: Best Summer Work Trousers: Lightweight & Breathable Options for UK Workers.
Safety footwear for hot weather
Feet overheat fast in heavy leather boots. Hot feet become painful feet. Painful feet mean distracted workers. Distracted workers make mistakes.
Footwear is the most overlooked part of summer PPE. Don't make that mistake.
Safety trainers vs safety boots
Safety trainers use mesh uppers. Air passes through directly. Feet stay far cooler than in a leather boot. Most safety trainers still carry S1 or S1P ratings — that's toe protection and an anti-penetration midsole.
For tougher outdoor terrain, you may need S3. That adds a water-resistant upper and more ankle support. You can still get S3 in a lighter, trainer-style build.
Steel toe vs composite toe
Steel toecaps conduct heat. In summer, that matters on your feet all day. A composite toecap — made from plastic or fibreglass — does the same protective job without conducting heat. It's lighter too.
Where site rules allow, composite toecaps are the better summer choice.
Browse summer footwear options in our Hot Weather Workwear collection.
For a full breakdown: Best Breathable Safety Shoes for Summer Work: UK Buyer's Guide.
Summer workwear for women
Most summer workwear guides ignore women. That's a problem. The female workforce in outdoor trades is growing. Women make up around 15% of the UK construction workforce — and that number rises each year across highways, rail, and utilities.
Unisex PPE often fails women in summer. Garments cut for a male body leave excess fabric. That extra material traps heat. It also catches on equipment and restricts movement.
What to look for in women's summer workwear
- A fitted cut shaped for a female body — not a unisex oversized garment
- Lighter gsm fabric — women's ranges often run 120–150gsm where men's equivalents run 160gsm
- Moisture-wicking as standard
- Hi-vis ratings that match site requirements — Class 2 or 3 where needed
We stock women's-specific summer PPE, from fitted hi-vis polos to lightweight cargo trousers. Browse our Ladies Summer Workwear collection.
For the full guide: Women's Summer Workwear: Lightweight & Breathable PPE for Female Workers in the UK.
Your summer workwear checklist for employers
Use this before you order. Tick every box and you'll have the right kit for your team.
- Fabric weight: 120–180gsm for tops; lightweight stretch for trousers
- Moisture-wicking: polyester or moisture-management fabric — not cotton
- UPF 40+ rated if workers are outdoors more than an hour daily in direct sun
- ISO 20471 class: match Class 1, 2, or 3 to your site's hi-vis rules
- Trousers: stretch for physical jobs; cargo for tool-carrying trades
- Footwear: mesh upper safety trainers with composite toecap where site rules allow
- Women on your team: order women's-specific cuts, not unisex oversized garments
- Check BS EN ISO 13688:2022 compliance on any garment sold as protective clothing
Frequently asked questions
Is breathable PPE still compliant with UK safety standards?
Yes. Breathable workwear can fully meet UK PPE standards. Look for garments that carry their specific certification — ISO 20471 for hi-vis, BS EN ISO 13688:2022 as the base standard for all protective clothing. Lighter fabric weight does not mean lower protection. The garment must be tested and certified to the relevant standard regardless of its weight.
What fabric weight is best for summer workwear?
For most summer workwear, look for fabrics in the 120–180gsm range. At 150gsm, a polyester hi-vis polo is light enough to stay cool through a full shift but tough enough for daily site use. Avoid anything above 220gsm in summer — heavy fabrics trap heat and slow your team down.
What is UPF and does my workwear need it?
UPF stands for Ultraviolet Protection Factor. A UPF 40+ rating means the garment blocks up to 97.5% of UV radiation. If your workers spend more than an hour daily in direct sun, UPF-rated workwear is strongly recommended. The HSE highlights skin cancer as a long-term risk of outdoor work. Look for garments tested to EN 13758-2 — this tests the finished garment, not just the fabric.
Can I wear a hi-vis t-shirt instead of a jacket in summer?
Yes, if the t-shirt or polo meets the hi-vis class your site requires. A Class 2 hi-vis polo, for example, gives the same visibility rating as a Class 2 jacket. Check your site's specific hi-vis rules first. If Class 3 is required — typically near live traffic at speed — you may need a long-sleeve garment to achieve the required fluorescent and reflective area coverage.
What are the signs of heat stress?
The HSE lists the key symptoms as muscle cramps, heat rash, heavy sweating, dizziness, severe thirst, nausea, and fainting. More serious cases bring heat exhaustion — the worker feels weak, pale, and confused. Heatstroke is the most serious stage: skin becomes hot and dry, the worker may become confused or lose consciousness. Heatstroke is a medical emergency. Cool the worker down immediately and call 999.
Is there a legal maximum working temperature in the UK?
No. There is no legal maximum working temperature in UK law. The HSE confirms this. But heat is still a legal hazard. Under the Management of Health and Safety at Work Regulations, you must assess the risks and put controls in place. That includes providing breathable PPE, rest breaks, shade, and cool water.
Summer PPE doesn't have to be a compromise. The right kit keeps your workers safe, keeps them cool, and keeps your site compliant. Pick the right fabric weight, the right hi-vis class, the right cut for your team — and you're done.
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