How to dress a newborn in summer: the calm guide

The first summer with a newborn brings a daily question: how do I dress the baby in this heat? Wrapped up too warmly and they sweat, too little on and you worry — and the unsolicited advice arrives from every direction, usually disagreeing with itself.

This guide sorts it out: how to dress a newborn in summer during the day, at night, indoors with the air conditioning on and outside in the sun, with the simple rules paediatricians use and the fabrics that genuinely help.

In short:

• The basic rule: in summer a baby wears what we wear, plus at most one light layer in the first months; above 24–25°C a bodysuit is often all you need.
• Only natural fibres against the skin: cotton, cotton muslin, linen. No synthetics that trap sweat.
• At night, in the heat: a bodysuit or light pyjamas, no blankets — a light sheet or a lightweight summer sleeping bag instead.
• The right check is on the back of the neck or the chest (warm and dry = fine), not on hands and feet, which are often cool.

How do you dress a newborn in summer during the day?

The direct answer: with a single light layer of cotton or muslin. Above 24–25 degrees, a short-sleeve or sleeveless bodysuit is often a complete outfit; between 20 and 24 degrees, add a light romper or a little set; below 20 (cool mornings, the mountains) a thin second layer is useful again, to be taken off as soon as it warms up.

The principle that settles every doubt: a newborn doesn’t need more layers than an adult, except in the very first weeks, when temperature regulation is still immature — that’s when the “+1 light layer” rule applies. After the first 2–3 months, dress the baby the way you would dress yourself.

• Above 25°C Sleeveless or short-sleeve bodysuit, legs free
• 20–24°C Bodysuit + romper or light cotton set
• Below 20°C Add a thin layer (cardigan, leggings)
• Air conditioning One layer more than ours, always light

The right fabrics for the heat (and the ones to avoid)

In summer the fabric matters more than the style. The ones that work:

• Cotton: the classic. Breathable, washable, gentle on the skin. For bodysuits and everything that sits against the skin.
• Cotton muslin: the queen of summer — a light double gauze that lets the air circulate and dries quickly. (We’ve given it a whole guide.)
• Linen and linen blends: cool and dry, perfect for little shirts and shorts in the months that follow.

To avoid: synthetics (polyester, acrylic) that trap sweat and heat, tight pieces that constrict, and anything with appliqués, sequins or raised seams against the skin. In summer too, the rule of flat seams and external labels applies — or labels removed altogether.

Farway pieces for the first months are made exactly this way: sleeveless cotton rompers to wear on their own on hot days or over a light bodysuit, in sizes 0–12 months from the Christening and Newborn collection.

How do you dress a newborn at night in summer?

The 23:47 question of every July. Direct answer: above 24–25 degrees in the room, a bodysuit is enough (short-sleeve or sleeveless); between 21 and 24 degrees, a bodysuit plus light pyjamas or a summer muslin sleeping bag (TOG 0.5–1); loose blankets aren’t needed and are not advised for the youngest babies — better a sleeping bag, which stays where it is.

Three small things that change the nights:

• Air the room before bedtime, and keep the cot away from the direct flow of fans or air conditioning.
• Ideal room temperature: 20–24 degrees; above that, take a layer off — never add one “just to be safe”.
• The back-of-the-neck check: warm and dry is fine; sweaty = one layer too many; cool = still fine (cool hands and feet are normal).

Out and about: sun, pushchair and the seaside

Direct sun is off-limits in the first months: the best protection is shade plus a brimmed hat, and light pieces that cover as much skin as they can (cotton is a gentle barrier). In the pushchair, never cover the hood with cloths or muslins “to make shade”: inside, the temperature rises quickly — better a proper sun shade and stops in real shade.

At the seaside or by the lake (we’ve written about some lovely ones an hour from Milan): short dips in the gentler hours, a dry change straight afterwards, and one more change of clothes in the bag than seems reasonable. It’s the law of summer: the number of changes you need is always n+1.

The baby’s mini summer capsule

For the first summer a few right pieces are enough, in the spirit of the essentials list we set out in the guide to the baby layette:

• 6–7 bodysuits, short-sleeve and sleeveless;
• 2–3 light rompers in cotton — the single most-worn piece of the summer;
• 1–2 sets or little dresses for occasions (lunch at the grandparents’ counts as an occasion);
• 1 thin cardigan for the air conditioning and the evenings;
• a hat, 2 multipurpose muslins, a summer sleeping bag.

Frequently asked questions

How do I tell if the baby is too warm?

Touch the back of the neck or the chest: if they’re sweaty or very hot, there’s one layer too many. Other signs: very red cheeks, irritability, heat rash (little red spots). Cool hands and feet, on their own, don’t mean the baby is cold: that’s the normal circulation of the first months.

Can a newborn wear just a nappy when it’s very hot?

In the hottest hours, indoors, yes — but a light cotton bodysuit is often more comfortable: it absorbs sweat and protects the skin from direct contact with surfaces and fabrics. Under air conditioning, always at least the bodysuit.

Which TOG should I choose for a summer sleeping bag?

For summer: TOG 0.5 for rooms above 24 degrees, TOG 1 between 21 and 24. Below that, you move to the mid-range TOGs. With TOG 0.5 a sleeveless bodysuit underneath is usually enough; with TOG 1, a bodysuit or light pyjamas depending on the temperature.

On a plane or a train with the air conditioning on full?

The strategy is layers: bodysuit + light romper + a cardigan to put on and take off. Air conditioning on public transport is unpredictable: a thin cardigan in the bag is the insurance that weighs nothing.

Are sleeveless rompers all right for sleeping too?

Yes, on warm nights they’re perfect over a bodysuit or on their own: they leave arms and legs free and don’t ride up. In summer they’re the most versatile piece in the layette — daytime, naps and family photos included.

Summer with a newborn, dressed well, is simpler than people make it sound: a few natural pieces, never one layer more than needed, and all the shade in the world. The meadows take care of the rest.