There's a real reason certain clothes feel like relief in a heatwave and others feel like punishment, and it isn't colour or cut — it's fibre. Once you understand which fabrics actually move heat and moisture away from your skin, you stop suffering in summer. This is the first in our Fashion Science series: the useful, evidence-informed why behind what we wear.
The coolest fabrics, ranked
1. Linen — the champion
Linen has a loose, breathable weave and hollow fibres that wick moisture and dry fast. It also holds itself slightly off the skin, so air circulates. It's the single best fabric for real heat — which is why every piece in our European Summer Formula leans on it. A linen maxi like the Matilda White Linen Sleeveless Maxi ($42.99) is, quite literally, engineered for heat.
2. Cotton — the reliable everyday
Cotton breathes well and absorbs moisture, though it holds it longer than linen (so it can feel damp after a lot of sweat). For everyday summer wear it's excellent — an eyelet cotton blouse like the Adèle Eyelet Long-Sleeve Cotton Blouse ($84.99), with its open eyelet weave, breathes even better than solid cotton.
3. Silk — the elegant option
Natural silk is breathable and temperature-regulating, and feels cool against the skin — ideal for dressier summer evenings, though it shows moisture.
The fabrics to avoid in heat
Polyester, nylon, and acrylic are the culprits. They're hydrophobic — they don't absorb moisture, so sweat sits on your skin, and their tight synthetic weaves trap heat. A clean white cotton or linen piece like the Sylvaine White Sleeveless Button-Down Maxi ($64.99) will always feel cooler than a synthetic in the same colour.
Two bonus rules from the science
Colour matters less than fibre, but light colours do reflect more heat than dark ones. And looser cuts beat tight ones — air circulation is half the battle. Natural fibre, light colour, loose cut: that's the formula for staying cool.
Frequently asked questions
What fabrics stay coolest in summer?
Linen is the coolest — its loose weave and hollow fibres wick moisture, dry fast, and hold off the skin for airflow. Cotton is a close, reliable second, and natural silk is breathable and cool for evenings. All three beat synthetics.
Why does linen keep you cool?
Linen has a loose, breathable weave and hollow fibres that wick sweat away and dry quickly, and it sits slightly off the skin so air can circulate. This combination moves heat and moisture away from the body better than almost any other fabric.
What fabrics should you avoid in hot weather?
Polyester, nylon, and acrylic — these synthetics are hydrophobic, so sweat sits on the skin, and their tight weaves trap heat. They tend to feel hot and clammy in summer.
Does fabric colour affect how cool you feel?
Somewhat — light colours reflect more heat than dark ones — but fibre and cut matter more. A loose, light-coloured natural fabric is the coolest combination.
Keep reading
More: Linen vs Cotton for Hot Weather, How to Choose the Perfect Vacation Dress, and the European Summer Packing List. Shop cool fabrics in Linen & Cotton, The White Linen Edit, and European Summer.
— Sabine