Wearing less isn't always the answer in summer. Learn how the right technical shirt and layers keep you cooler, safer, and sun-protected outdoors.

When the sun comes out, the instinct is to strip off. But if you're heading into the hills, traversing open ground, or spending time at altitude, less clothing is rarely the right answer.

The right layer keeps you cooler by managing airflow while blocking harmful UV rays. It protects your skin without trapping heat. And it moves with you rather than against you.

This guide explains how to layer intelligently for summer: what to wear, why it works, and how to choose the right pieces for the conditions you're in.

Wearing more can keep you cooler

It sounds counterintuitive. But bare skin in direct sun absorbs heat. A well-designed shirt diffuses it.

A lightweight, breathable shirt creates a thin buffer of moving air between fabric and skin. That buffer keeps you cooler than unprotected skin in the same conditions. The fabric also intercepts UV radiation before it reaches you.

At altitude, UV increases significantly with every 1,000 metres you gain. Thinner air scatters less radiation. You burn faster, and the cumulative effect builds gradually, making it easy to dismiss until the damage is done. A day on the high tops in summer without adequate protection is not just uncomfortable. It is a long-term skin health risk.

The shirt: your most important summer layer

A technical summer shirt does several jobs at once. It manages heat, blocks UV, moves with your body, and stays comfortable across a long day.

A standard cotton shirt holds moisture, loses its shape and offers very little UV protection. A technical shirt is a fundamentally different piece of kit. Here's what separates a well-made outdoor shirt from a regular one.

Loose fit with articulated construction. Our shirts use a loose fit to encourage airflow across the body. The articulated cut means the shape stays consistent whether you're reaching overhead, crouching to pack your bag, or hiking under a rucksack. The fit moves with you rather than fighting you.

The collar as a sun shield. Worn up, the collar shields the back of the neck during sustained sun exposure. This is one of the most exposed areas on your body and one of the most overlooked. On a long, sunny ridge walk or an open bike route, it makes a real difference.

Dual-position cuff adjustment. Push the cuffs back when you need airflow. Fasten them down when the sun gets intense or the temperature drops. Simple, and far more useful than it sounds across a long day.

Practical features built into your shirt. The sunglasses slot on the chest pocket solves an irritating problem. When you're repeatedly moving between shade and open ground, having somewhere to clip your glasses without fishing in a pocket saves time and frustration.

Synthetic performance with a soft cotton feel

When the sun is out and you're working hard, the starting point is simple: light, breathable, and fast-drying. Technical lightweight shirts are built for exactly this scenario. Using synthetic fibres they are significantly lighter than any other shirt, dry quickly after rain or a river crossing, and carry a UPF 50+ rating for sun protection. No creases, no odour retention, and easy to rinse out and dry overnight on a multi-day trip. We also choose modern fibres with a natural feel against the skin.

You will find these traits right across our range; Coruna, Rocca, Aneto, Nevero, Kanza, Cinca, Veleta, Esla, Kanza mountain shirts are examples that stand out.

Woodsmoke is known for keeping you warm. Its Thermocore hollow core fibres trap air close to the body, which is exactly what you want when the temperature drops. But that same hollow core structure works in reverse in the heat. Rather than simply reacting to temperature, the fabric regulates it. The trapped air buffers against radiant heat from the sun the same way it insulates against the cold. So if you're heading somewhere where the morning starts cold and the midday sun is intense, or moving between valley and ridge throughout the day, Woodsmoke earns its place in a summer pack in a way most people don't expect.

Add natural odour resistance, four-way stretch, and no-iron performance, and it holds up across a long trip in a way the lighter shirts don't need to.

UPF ratings and what they mean

UPF stands for Ultraviolet Protection Factor. Think of it as the clothing equivalent of SPF in sun cream, applied to fabric.

A UPF rating of 50 means the fabric blocks around 98% of UV radiation. Only 1 in 50 UV rays passes through the material. That's meaningful protection across a full day outdoors.

Fabric construction drives this rating. Tightly woven synthetics, such as polyester and nylon, leave very little gap for UV to penetrate. Loose weaves and natural fibres like untreated cotton offer far less. A pale, untreated cotton shirt has very little UPF value at all.

Some fabrics are also treated during manufacturing to enhance their UV-blocking properties. Colour plays a role too: darker fabrics absorb more UV radiation, while lighter colours reflect more heat. In our Cinca range we deliberately use lighter colours for this reason.

UPF 50+ is the standard we build into our lightweight shirt range and across our broader technical lineup, a deliberate choice in fabric selection.

UV protection across your full kit

Shirts are the hero here, but UV protection runs through everything we design for summer use.

Swimwear. Our swim range is rated at 50+ UV protection. So while you're in and out of the water, your protection doesn't drop.

Wetsuits. Our Yulex wetsuits offer the highest level of UV and ozone blocking in the range, with the best breathability in the wetsuit lineup. That matters for long days on the water where total exposure adds up over time.

Legwear. Our Teleki trousers are rated at 40+ UPF. It's a woven fabric, which gives it stronger UV-blocking properties than knitted alternatives. For high-altitude trekking or long days on open ground, pairing a UV-rated shirt with UV-rated legwear closes the gap and gives you consistent protection head to foot.

One practical note: if you're using waterproof or DWR-treated items alongside sun cream or body oils, try to keep the two separate. Oils and creams can clog the breathable membrane and degrade the DWR treatment. If they do come into contact, wash the item promptly to restore its performance.

Altitude and travel

At 2,000 metres, UV exposure is roughly 20% higher than at sea level. At 3,000 metres, closer to 30% higher. Every 1,000 metres of altitude reduces atmospheric protection and increases the intensity of radiation reaching you.

For hillwalking, mountaineering, or any extended time on open high ground, this is a genuine concern. Cumulative exposure across a season or a lifetime of days in the hills adds up faster than most people realise. A well-rated shirt and the habit of keeping your collar up costs very little against that background.

The same logic applies when travelling. A technical shirt that packs small, dries quickly, and offers real UV protection earns its place in a travel bag. You're not carrying extra weight: you're replacing a less capable garment with one that does considerably more.

Choosing the right summer layer

The right shirt depends on what you're doing and where you're doing it.

Choose from the lightweight range if weight and packability are the priority. Fast-drying, crease-free, and genuinely light. The UPF 50+ rating and Polygiene® odour control make these the better choice for extended travel or humid conditions where you need to do more with less kit. For which shirt specifically, see our summer shirts buying guide.

Choose Woodsmoke if you're moving between significantly different conditions across the day. The Thermocore fabric handles a broader temperature range and is a strong choice for cross-season use, or destinations where mornings are cool and midday sun is intense.

For days on or in the water, protect yourself with a UV-rated Hurley, Dulsie or Nessie.

For days in the valley and on the hill layer a technical shirt over UV-rated legwear or baselayer. The goal is consistent coverage across all exposed surfaces, from fabric you can trust across a long day.

And don't forget to lube up those remaining exposed areas.