How to Dress Your Baby in the Summer: A Complete Guide by Temperature

As the weather starts to warm up, the same question comes up every year: How should you dress your baby in the summer? Babies have trouble regulating their body temperature and can’t tell us if they’re hot or cold. Dressing them too warmly or not warmly enough can lead to discomfort—or even complications. Here’s the complete guide to dressing your baby smartly when temperatures rise. ☀️

🌡️ Why Babies Have Trouble Tolerating the Heat

Infants and young children have an immature thermoregulatory system. Unlike adults, they do not sweat effectively until several months of age and cannot release heat through sweating the way we do. As a result, they overheat more quickly and need outside help to maintain a stable body temperature.

Overheating is a risk factor for sudden infant death syndrome (SIDS)—which is why it’s important never to cover your baby too much, even in winter. In summer, you need to be even more vigilant.

👕 The basic rule: wear one more layer than you would

The classic pediatric rule for dressing a baby: one more layer than what you’re wearing. If you’re wearing a T-shirt, your baby should wear a T-shirt plus a light layer. But in the summer, when temperatures exceed 25–26°C, this rule becomes more flexible: your baby can wear the same thing as you—or even less.

The best indicator is still the baby's neck: warm and damp = too hot; cold = too cold; lukewarm and dry = just right.

👗 How to Dress Your Baby Based on the Temperature

Less than 20°C (cool summer mornings)

• bodysuit long sleeves + lightweight jumpsuit
• Or lightweight cotton pajamas + a transitional " sleep sack "
• A light layer for outings

20 to 24°C (mild weather)

• bodysuit short sleeves + onesie or lightweight overalls
• At night: lightweight cotton pajamas, lightwe sleeping bag e (TOG 0.5)

25 to 30°C (on hot days)

• bodysuit on its own or as part of a very light short-sleeved outfit
• Wide-brimmed hat for outings in the sun
• At night: bodysuit alone or paired with an ultra-light sleeping bag (TOG 0.2)

Over 30°C (extreme heat)

• Sleep alone at home if the room is cool
• bodysuit Very lightweight, made of bamboo or ultra-fine cotton, perfect for outings
• At night: sleep alone if the room temperature exceeds 26°C
• Refresh regularly with a water spray bottle

👘 What fabrics should you choose for summer baby clothes?

• Organic cotton: the gold standard. Breathable, soft, and hypoallergenic. OEKO-TEX-certified cotton is free of chemicals that can irritate a baby’s delicate skin.
• Bamboo: even softer than cotton, naturally temperature-regulating and antibacterial. Ideal for sensitive skin and babies who sweat easily.
• Lightweight linen: cool and breathable for older children.
• Avoid: polyester, acrylic, nylon—these synthetic materials do not absorb sweat and can cause irritation in hot weather.

☀️ Sun Protection: Guidelines for Babies

The sun is dangerous for babies' delicate skin—much more so than for adults. Official recommendations:

• Before 6 months: Avoid any direct exposure to the sun. Stay in the shade, use a stroller sunshade, and dress your baby in lightweight, covering clothing.
• After 6 months: Apply SPF 50+ sunscreen to exposed areas (face, hands, legs), reapplying every 2 hours and after each time you go swimming.
• Hat: a must-have as soon as the sun starts to shine. Choose a wide-brimmed hat or a cap with neck protection.
• UV-protective clothing: For extended time in the sun (beach, pool), UV-protective suits offer better protection than any sunscreen.

To help you get ready for your summer outings with your baby, our guide on what to pack in a diaper bag will help ensure you don't forget anything—sunscreen, a change of clothes, a hat.

😴 Babies and Heat at Night: How to Get a Good Night's Sleep?

Nighttime heat often disrupts babies' sleep. Here are a few tips:

• Ideal room temperature: 18–20°C. In the summer, if you don’t have air conditioning, a fan pointed at the ceiling (never directly at the baby) helps circulate the air.
• sleeping bag Choose the right one for the season: use the TOG rating. TOG 0.2–0.5 for warm rooms (24–27°C), TOG 1 for cool rooms (20–24°C).
• No blanket: Before 12 months of age, do not use a blanket in the crib— sleeping bag s are always safer.
• Air out the room in the evening: open the windows at night when the outside temperature drops, and close the shutters and curtains in the morning to keep the room cool.

🧺 Summer Baby Wardrobe Essentials

• Short-sleeved or sleeveless bodysuits: 5–7 bodysuit are enough for a week
• Lightweight onesies: practical, breathable, and cute for outings
• Lightweight jumpsuits: for cooler evenings
• Slippers or open-toed shoes: feet are often overlooked, but they sweat too
• Wide-brimmed hat: a must-have for any sunny outing

Check out our selection of lightweight baby rompers and onesies —made from soft, breathable fabrics to help you enjoy a carefree summer.

❓ FAQ — Dressing Your Baby in the Summer

How can you tell if your baby is too hot?

Signs of overheating: a hot, clammy back of the neck; red skin (especially on the face and neck); restlessness or, conversely, unusual lethargy; and rapid breathing. If your baby is significantly overheated, remove a layer of clothing, offer a breastfeed or a bottle of water, and if your baby has a fever above 38°C, consult a doctor.

Can I put my baby in a swimsuit at the pool?

Yes, along with a hat and SPF 50+ sunscreen. For extended stays, a UV-protective one-piece swimsuit that covers the arms and legs is recommended. Never leave your baby exposed to direct sunlight between 11 a.m. and 4 p.m.

Should you give your baby water in the summer?

Before 6 months of age, breast milk or infant formula provides all the necessary hydration—no additional water is needed. After 6 months, offer plain water in small amounts between meals, especially in hot weather.

🛍️ Dressing Your Baby in the Summer with PetitMaxou

Bodysuits, rompers, and lightweight onesies made from soft cotton: PetitMaxou offers a summer collection designed with your baby’s comfort and safety in mind. Soft, breathable fabrics; colorful and practical designs. Free shipping throughout the EU.

→ View the entire baby clothing collection PetitMaxou

🏖️ Checklist for a trip to the beach or pool with a baby in the summer

A trip to the water with your baby requires some special preparation. Here’s what you shouldn’t forget:

• SPF 50+ sunscreen suitable for babies (apply 30 minutes before sun exposure)
• Wide-brimmed hat or cap with neck protection
• UV-protective coveralls for extended exposure to the sun
• Swimsuit + swim diaper (different from a regular diaper)
• Bathrobe or towel for after a bath
• Water or breast milk for hydration (before 6 months, no additional water)
• Shade: UPF 50+ beach umbrella or beach tent

To make sure you don't forget anything when you're out and about with your baby, our comprehensive guide on what to pack in a diaper bag will give you a complete checklist organized by age group.

🌬️ Keeping Your Baby Cool in Hot Weather: What to Do

When temperatures exceed 30°C, here are some steps to help your baby cope with the heat: regularly mist their face and limbs with lukewarm water (not cold—the temperature shock is counterproductive); offer more frequent breastfeedings or bottle feedings, as their need for hydration increases; give them a lukewarm (not cold) bath in the middle of the day to lower their body temperature; keep the room cool by closing shutters and curtains in the morning and airing it out at night; and watch closely for signs of overheating—a sweaty neck, redness, lethargy, or unexplained irritability.