Quick answer
For hot weather, linen is the most breathable choice and dries fastest against the skin, GOTS-certified organic cotton is the safest all-round pick for sensitive skin, and bamboo viscose sits in between as a soft, moisture-wicking option. Whatever the fabric, loose and oversized fits, light colours, and UPF-rated coverage matter just as much as fibre choice.
Why fabric matters more once it gets properly hot
Amsterdam summers have been getting sweatier, and a warm spell turns "what should they wear today" into a real question rather than a habit. Children regulate their body temperature less efficiently than adults, and babies especially can go from comfortable to overheated quickly. Watch for fussiness, flushed skin, rapid breathing, and heavy sweating — if you spot these, move your child somewhere cooler, remove a layer, and offer fluids straight away.
Fabric is one of the few things you can control on a hot day. The right one moves moisture away from the skin instead of trapping it there, which is exactly how heat rash and general crankiness show up on the sweatiest afternoons.
Cotton, linen, and bamboo — how they actually compare
All three are natural fibres, so they all breathe far better than synthetic blends. But they don't behave identically once a child starts sweating.
| Fabric | Best for | Trade-off |
|---|---|---|
| GOTS organic cotton | Everyday wear, sensitive skin, year-round use | Holds moisture against skin longer than linen once it's really humid |
| Linen | Peak breathability on the hottest days | Wrinkles easily, less common in baby sizes |
| Bamboo viscose | Very soft feel, sensitive or eczema-prone skin | Heavily processed fibre; check for certified, low-impact processing |
Conventional cotton absorbs moisture and holds it against the skin rather than wicking it away, which is why cotton clothing can start to feel clammy on a humid day. Linen absorbs a large share of its own weight in moisture before it feels damp, so it releases heat and dries faster — that's the mechanism behind its reputation as the cooler fabric. Bamboo-based fabrics are often described as noticeably more breathable than standard cotton and several degrees cooler against the skin, alongside a naturally soft handle that suits reactive skin.
None of this makes cotton a poor choice. GOTS-certified organic cotton remains the most practical everyday fabric for babies and toddlers: it's widely available, well tested, machine-washable at high temperatures, and free from the pesticide residues and finishing chemicals that can irritate young skin. On the very hottest days, treat linen and bamboo as useful additions to a wardrobe built primarily around organic cotton, rather than a full replacement for it.
What to actually put them in during a heatwave
Fibre choice is only half the equation — cut and colour do the rest of the work.
- Go loose, not tight. Loose-fitting, lightweight clothing allows air to circulate around the body instead of trapping heat against it, which is exactly what an oversized cut is designed to do.
- Choose light colours. Pale shades reflect heat rather than absorbing it the way darker colours do.
- Undress before you overdress. On the hottest days, a short-sleeve bodysuit — or just a nappy — can be enough for a young baby; toddlers do well in light shorts, a breathable t-shirt, and a sun hat.
- Rethink sleepwear. A 0.5 TOG sleep bag suits rooms around 24–26°C, while on very warm, un-air-conditioned nights a simple bodysuit alone may be all that's needed — check your specific product's TOG chart against your room temperature rather than the calendar.
- Keep hydration close by. Milk, formula, or water for babies over six months should be offered more often in the heat, especially on days out.
Do they need UPF clothing as well as sunscreen?
Dermatologists generally rank UPF (UV Protection Factor) clothing above sunscreen for children, mainly because it doesn't wash off, sweat off, or need reapplying. Children are exposed to the sun considerably more than adults simply by virtue of being outside more, which is why sun-protective fabric is worth building into a summer wardrobe rather than treating as an extra purchase.
For babies under six months, clothing and shade are the primary line of defence, since sunscreen isn't recommended for that age group. Look for a UPF 50+ rating on the label for anything worn during peak sun hours, and pair it with a wide-brimmed hat — fabric can't protect the face and neck on its own.
Our take
We build our collection around GOTS-certified organic cotton because it holds up to daily wear, repeated washing, and handing down between siblings better than delicate summer fabrics tend to — and the oversized, gender-neutral cuts already do a lot of the "keep them cool" work that a heatwave calls for. If you're layering in linen or bamboo pieces for the hottest stretch of summer, treat them as an addition to a cotton-based everyday wardrobe rather than a seasonal wholesale swap.
FAQ
Is linen safe for a baby's sensitive skin?
Yes, for most babies — it's a natural fibre with no known higher irritation risk than cotton. If your child has eczema or very reactive skin, introduce any new fabric gradually and watch for a reaction, the same way you would with a new cotton garment.
What TOG rating should I use for summer nights?
A 0.5 TOG sleep bag generally suits rooms around 24–26°C. On very hot, un-air-conditioned nights, a bodysuit alone without any sleep bag may be more comfortable — always match the rating to your actual room temperature.
Do I still need sunscreen if my child is wearing UPF clothing?
Yes, for any exposed skin — face, hands, and feet still need sunscreen (for babies over six months) or shade and a hat (for babies under six months). UPF clothing covers what it's covering, nothing more.
What are the signs my child is overheating?
Fussiness, flushed skin, rapid breathing, and heavy sweating are the main signs. Move them somewhere cooler, remove a layer, and offer fluids — contact a doctor if symptoms don't ease quickly.
Is bamboo fabric actually cooler than cotton?
It's generally reported as noticeably more breathable and a few degrees cooler against the skin than standard cotton, thanks to its moisture-wicking structure. It's a good option for hot nights, though check that it's certified and produced with a low-impact process.
Is organic cotton breathable enough for a heatwave?
Yes, especially in a loose, oversized cut and light colour — it just holds onto moisture a little longer than linen once conditions get very humid. For most days, well-cut organic cotton is all a child needs.