Seed to Sleep

Blog · 11 October 2025

What Should My Baby Wear to Sleep?

What Should My Baby Wear to Sleep? A Season-by-Season Guide for Parents

Knowing how to dress your baby for sleep can be a challenge especially when the seasons change or temperatures fluctuate. Should they wear a onesie? Do you need a sleep sack? Is it ever okay to use a blanket?

The general rule of thumb is simple: dress your baby in one more layer than you would wear yourself. This applies both during the day and at night.

In this blog, we’ll walk you through exactly how to dress your baby for sleep from newborns to older babies based on temperature, safety guidelines, and comfort. Whether it’s summer, winter, or somewhere in between, you’ll be equipped to make the best choice for a good night’s sleep.

👶 How to Layer for Sleep: The One Extra Rule

The “one extra layer” rule is backed by healthcare professionals and is a great starting point for new parents. For example, if you’re wearing a light t-shirt to bed, your baby might wear a short-sleeve onesie plus a sleep sack or long-sleeve layer.

Remember: all babies under 12 months should be placed to sleep on their back and in a cot free of loose blankets or toys.

🧸 Types of Baby Clothes for Sleep

Here’s a breakdown of the most common (and useful) baby sleepwear options:

  • Baby Gowns: Great for the early newborn stage. Open at the bottom for easy nappy changes and gentle on the umbilical cord stump. You can tie or leave them loose depending on temperature.
  • Footed Sleepers: These one-piece pyjamas cover your baby from shoulders to toes and are ideal for cooler nights.
  • Onesies: A base layer that can be short- or long-sleeved. Perfect for layering under a sleep sack or sleeper.
  • Swaddles: Used for newborns who haven’t started rolling yet. Swaddles keep babies snug, calm, and warm. Stop swaddling once your baby shows signs of rolling (usually around 2 months).
  • Sleep Sacks: Also known as wearable blankets, these are the safest option for keeping older babies warm at night. They come in different thicknesses (measured in TOG).

🧵 Best Fabrics for Baby Sleepwear

  • Muslin: Lightweight, breathable, and perfect for warmer nights.
  • Jersey Knit: Stretchy, soft, and great for year-round comfort.
  • Fleece: Super cosy and warm ideal for cold winter nights.
  • Polyester: Durable and moisture-wicking, often used in sleep sacks and outerwear.

🎩 Should Newborns Wear Hats to Sleep?

No. Health experts, including the American Academy of Paediatrics, recommend avoiding hats indoors after the first few hours of life. Hats can lead to overheating, which is a known risk factor for SIDS (sudden infant death syndrome).

🌡️ How to Dress Your Baby Based on Room Temperature

Use this guide to help you choose the right sleepwear based on your baby’s room temperature. The TOG (Thermal Overall Grade) rating tells you how warm a sleep sack or swaddle is.

Room Temp (°F)

What Baby Can Wear

TOG Rating

80°+

Nappy only

N/A

78°

Short-sleeve onesie

N/A

75–77°

Onesie + light swaddle or sleep sack

0.5 TOG

71–74°

Long-sleeve pyjamas + swaddle or sleep sack

0.5 TOG

69–70°

Onesie + pyjamas + sleep sack

1.0 TOG

64–68°

Long-sleeve onesie + pyjamas + sleep sack

1.0 TOG

61–63°

Socks + long-sleeve layers + warmer sleep sack

2.5 TOG

Below 60°

Mittens + socks + layers + thickest sleep sack

2.5 TOG+

💡 Tip: If you’re not sure of the room temperature, a simple room thermometer is a great investment for baby sleep safety and comfort.

❄️ How to Dress Baby for Winter or Cold Nights

In winter, or if your home tends to be chilly or drafty, you may need more layers. A good combo might be:

  • Long-sleeved onesie
  • Fleece or flannel pyjamas
  • 2.5 TOG sleep sack

Avoid using blankets in the cot. Instead, rely on warm, breathable sleepwear and a safe sleep environment.

☀️ How to Dress Baby on Warm Nights or in Summer

Babies sleep best in rooms between 68–72°F (20–22°C), but sometimes you can’t control the heat. In warmer weather:

  • Choose breathable fabrics (like cotton or muslin)
  • Use lighter sleep sacks (0.2–0.5 TOG)
  • Avoid overheating by removing layers if needed

🔍 Signs your baby may be too hot:

  • Red cheeks
  • Sweaty hairline
  • Fast breathing
  • Fussiness
  • Heat rash
  • Feels hot to the touch

If you notice these, remove a layer and cool the room if possible.

❄️ How to Dress Baby for Sleep with Air Conditioning

If your home is air conditioned, dress your baby in:

  • Pyjamas + light sleep sack, or
  • Onesie + medium-weight sleep sack

Avoid placing your baby directly under the AC vent. If possible, redirect the airflow or adjust the temperature to stay within the 68–72°F (20–22°C).

✅ Creating a Comfortable Sleep Space

Beyond sleepwear, these extras can help your baby feel safe, calm, and cosy:

  • White noise machine: Mimics the womb and masks background noise
  • Blackout curtains: Supports melatonin production and helps your baby nap longer
  • Lavender or chamomile: Calming scents (used safely and sparingly)
  • Leak-free nappies: Use ultra-absorbent nappies for overnight to avoid wake-ups from wetness