How to Dress a Baby in a Heatwave: A UK Parent's Guide

British summers used to be a light cardigan affair. Now we get real heat — and with it, the same worried question from every parent: what should my baby actually wear? Here is the calm, practical answer.

The one rule that matters

Babies can't regulate their temperature the way adults do, so the goal is simple: one light, breathable layer more than nothing — and a fabric that lets heat escape. In a heatwave, less really is more.

During the day

• Indoors (20–24°C): a single short-sleeve bodysuit is usually enough. An envelope-neck or crossover bodysuit makes changes easy without pulling anything over a hot, bothered head.
• Very hot days (25°C+): a nappy and a light bodysuit — or just the nappy at the peak of the afternoon — is perfectly fine at home.
• Out and about: light, loose layers like a breathable summer set, a brimmed bonnet for shade, and never a blanket draped over the pram (it traps heat like a greenhouse — use a clip-on parasol instead).

At night

The nursery ideal is 16–20°C, but heatwave nights run hotter. As a guide:

• 24–27°C: just a short-sleeve bodysuit, or a vest with a 0.5 tog sleeping bag.
• 27°C+: a nappy alone is fine. A folded cotton sheet is safer than any blanket.

For toddlers who've graduated to pyjamas, choose a loose, breathable short-sleeve set and keep bedding minimal.

How to tell if baby is too hot

Feel the back of the neck or chest — not hands and feet, which often run cool. Warning signs: damp hair, flushed cheeks, rapid breathing, unusual fussiness. If in doubt, remove a layer and offer a feed.

Why the fabric is half the answer

Synthetic fabrics and heavy cottons trap heat and moisture against the skin. Long-staple organic Egyptian cotton — the softest cotton in the world — is naturally breathable and moisture-wicking: it draws warmth away instead of sealing it in, which is why it has dressed babies in hot climates for generations. Every Caico piece is 100% organic Egyptian cotton, GOTS certified, with no synthetics anywhere near delicate skin.

Stay cool out there — and if you're building a summer drawer, our Baby Summer Set and Short Sleeve 3-Pack are where most parents start. First order? Code WELCOME10 takes 10% off.