Safer Snuggles - Your Guide to Dressing Baby for Winter Sleep with The Lullaby Trust

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Winter is here. The temperature drops, and the parent worry rises: Is my baby warm enough? Getting the layering just right is the secret to a more comfortable, safer sleep for your baby and for your own peace of mind. 
Genevieve Titov, Sleep Angel
5 min read |
26 November, 2025

Love To Dream: Safer, Simple Sleep Solutions 

We've teamed up with our charity partner, The Lullaby Trust, to bring you a step-by-step guide on dressing your baby (6 months and up) safely for sleep during the winter months. 

Focus on the Room, Not the Weather 

The official recommendation from The Lullaby Trust is that the ideal room temperature for a baby to sleep is between 16 -20°, with 18° being just right. You should keep a thermometer near your baby's sleep space, so you can monitor the temperature in the room.

Key Call out: If your baby’s room regularly dips below 18° in winter, you may want to consider adjusting their clothing and sleepwear layers to better suit the room temperature.

Understanding TOGs: Your Sleepwear Thermostat 

A TOG (Thermal Overall Grade) rating is a unit of measurement that refers to the amount of insulation in sleepwear. 

  • The Science: The lower the rating, the lighter the fabric. The higher the TOG, the thicker and more insulated the fabric. 
  • The Benefit: Understanding TOG ratings makes it easier to choose the right level of warmth and stop guessing what to dress your little one in. 

Temperature Control: Safety First 

Crucial Safety Advice:  While it can be tempting to wrap your baby up to keep them warm and cosy, it’s important to remember that this can cause them to overheat, and this increases the risk of sudden infant death syndrome (SIDS). In fact, research has shown that babies are safer when they’re a little bit cooler, rather than too hot.   

Your Winter Dressing Guide (6+ Months) 

Some of the key things you need to understand when it comes to winter dressing are the TOG rating of your baby’s sleep sack or sleep suit and what clothing layers should be worn underneath. 

TOG Rating
Clothing Layers
Less than 16° 

3.5 TOG
Long-sleeve bodysuit or vest + Long-sleeve pyjamas (footed or footless).
16°– 18° 

2.5 TOG
Long-sleeve bodysuit or vest + Long-sleeve pyjamas.
18°–24° 

1.0 TOG
Short-sleeve vest + Long-sleeve pyjamas OR just long-sleeve pyjamas.

Winter Layering Breakdown 

For babies over 6 months, their base layers should fit snugly and be made of breathable, natural
fabrics like cotton or bamboo. 

  • Base Layer (The Vest/Bodysuit): This is the layer closest to the skin. It helps wick away sweat and maintains an even temperature. 
  • Middle Layer (Pyjamas): A full-length set is your second insulating layer. Footed pyjamas are great for keeping little feet warm in colder rooms. 
  • Outer Layer (The Sleep Sack/Suit): Sleep sacks come in a range of TOGs so you can easily adjust to the room temperature and remove the risks associated with having loose blankets in the cot.

TOG Rating & Fabric 
Key Winter Benefit 
The Go-To Layer: Sleep Suit™ 

2.5 TOG / Merino
Designed with built-in legs, perfect for active toddlers who stand or walk. Perfect for typical winter rooms that measure between 18° C–20° C
The Deep Winter Layer: Sleep Bag 

3.5 TOG / Merino
Ideal for very cold bedrooms that often fall below 16° C, so you can keep your baby at a comfortable temperature without needing to use unsafe, bulky blankets.

Layering Essentials 

For a base and middle layer, to complete the ensemble, ensure the clothing underneath the sleep sack is lightweight and breathable. Our bamboo layers make dressing simple and comfortable with buttery soft bamboo as the layer closest to the skin. 

Safety Checklist: Winter Sleep 

Always follow these key safety points, as recommended by The Lullaby Trust: 

  • No Hats For Sleep: Never put a hat on your baby indoors or while sleeping, as this can cause them to overheat. 
  • No Loose Bedding: Do not use pillows, quilts, or heavy duvets in the cot. The sleep sack is considered to be a safer alternative for loose blankets and can be a great way to keep them warm and comfortable. 
  • Position is Key: Always place your baby to sleep on their back. 
  • Avoid Over-Dressing: Stick to the guide above. If the room is below 16° C consider adding an additional layer of clothing or increasing the TOG rating of the sleep sack.
  • Avoid using electric blankets, hot water bottles or heaters near the cot. Babies can’t regulate their own temperature, so they could get too hot.

By monitoring the temperature of the sleep space and choosing the appropriate TOG-rating for your baby's sleepwear, you can rest well knowing your baby will be perfectly comfortable all winter long.

Did you know?..

If your baby is unwell with a cold or fever don’t be tempted to wrap them up more than usual. Your baby should be dressed for their environment. You could also use The Lullaby Trusts Baby Check App to help you assess if your baby needs to see a health professional.

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