What is a TOG rating?

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Whether you're expecting, deep in the newborn trenches or in the toddler vortex, you've probably come across the term TOG and thought…sorry...what? Do I need a degree in sleepwear? What is happening. We hear you, you've come to the right place - welcome to our TOG talk.
reviewed by Genevieve Titov, Sleep Angel
8 min read |
31 January, 2025
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What does TOG mean?

TOG stands for Thermal Overall Grade. It's a unit of measurement that tells you how warm a fabric will keep your baby. This makes dressing your baby simpler and safer as both overheating and loose layers like blankets, can pose a risk to infant sleep.

You'll see TOG ratings on quality and tested sleep bags, swaddles, and sleep suits. Underneath those, you dress your baby in breathable layers, as recommended on a dressing guide.

Put simply:

The lower the TOG rating, the lighter and less insulating the fabric.

The higher the TOG rating, the warmer and more insulating the fabric.

What TOG do I need?

Set your baby's room temperature and we'll show you which TOG to use and what to wear underneath.

Step 1

What's the temperature in your baby's room?

Start with your baby's room temperature at bedtime to see recommendations on TOG for your sleeping bag and what to wear underneath.

Step 2

At 18°C, you have two options

2.5 TOG | 16-20˚C
Swaddle Up™ or sleeping bag2.5 TOG
UnderneathBabygrow and sleeveless bodysuit
Shop 2.5 TOG
1.5 TOG | 18-22˚C
Swaddle Up™ or sleeping bag1.5 TOG
UnderneathBabygrow and short-sleeve bodysuit
Shop 1.5 TOG

Every child is different. The number of clothing layers may vary according to health, physiology and room temperature. This guide is general advice only.

Safety tip

 When in doubt, go with the lower TOG. It's always safer for baby to be slightly cool than too warm.

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Why TOG Ratings Matter for Safer Sleep

Getting the right TOG isn't just about comfort. It plays a part in safer sleep:

  • Babies can't regulate their own body temperature the way adults can, especially in the first 12 months.
  • If they're dressed too warmly, they're at higher risk of overheating, which is a known risk factor for SIDS (Sudden Infant Death Syndrome).
  • Similarly, if they're too cold, they might wake frequently and struggle to settle.

Following a dressing guide and using the right TOG for your baby's room temperature helps reduce the risk of overheating.

A comfortable, fitted swaddle or sleeping bag also removes the risk of covers being kicked off or loose layers pulled over baby's face. A sleeping bag or Swaddle Up™ stays in place, so it gives more predictable and even warmth than loose blankets.

Learn more: Safer Sleep Guidelines for babies

TOG Ratings by Season

The UK climate can be unpredictable, but here's a general guide to help you plan ahead.

Summer

June to August. British summers can vary wildly. On warmer nights when your nursery creeps above 24°C, a 0.2 TOG is the safest bet. On especially hot nights, baby might just need a vest or even just a nappy underneath. For most typical summer evenings where the room sits around 20-24°C, a 1.0 TOG with a short-sleeve bodysuit works well.

Autumn & Spring

September to November, March to May. The shoulder seasons are the trickiest because temperatures can swing from warm days to cool nights (and then back again). Having both a 1.0 TOG and a 1.5 TOG on hand means you can switch depending on the evening. Check your nursery temperature at bedtime rather than going off the weather forecast. Already have a 2.5 TOG? It can be worn up to approximately 20°C, but layer accordingly and check for signs of being too hot.

Winter

December to February. For most winter nights, a 2.5 TOG will do the job. If your home gets really cold overnight (below 16°C), which is common in older UK homes, step up to a 3.5 TOG. Layer a long-sleeve bodysuit underneath and you're sorted.

What to Dress Baby in Under Each TOG

The TOG rating covers the sleep bag or swaddle itself, but what baby wears underneath matters too. There is some flexibility to layer up and down within the temperature range, to get the most value from your TOG-rated sleepwear.

Choosing a lightweight, breathable layer that is soft and has slight stretch will allow for comfort, movement and sit flat against the skin under their TOG rated sleepwear.

These are general guidelines. Every baby is different so always check if they are too hot or cold and adjust a layer accordingly. 

TOG temperature chart

This chart is our room temperature guide in one picture. It shows the same TOG and layering advice for every temperature at a glance. Save it to your phone so it's there at nap time and bedtime, or scroll up and enter your room temperature for your recommendation.

TOG for Newborns vs Babies vs Toddlers

The TOG rating itself doesn't change based on your baby's age. Correct TOG testing will ensure the TOG is relevant to the garment, and not the baby's age or sleep development stage. Here are a few tips when dressing your baby with a TOG rated swaddle or sleep bag:

Newborns (0 to 3 months)

  • Newborns are still learning to regulate their temperature, so they're more sensitive to being too hot or too cold. Generally, the mid TOG ratings (1.0 or 1.5) are a great start unless your home is very cold. Our 1.5 TOG swaddle is a popular choice for newborns as it provides a little more warmth which can be preferable for a hospital environment as well.
  • Shop TOG rated swaddles for newborns

Babies (3 to 6 months)

  • This is when most babies transition from a swaddle to an arms-free sleep bag. The Love to Dream™ Transition Bag makes this easy with zip-off wings, whilst still offering the snug security of the swaddle they love but soon, they will be arms free! They are TOG rated so the same logic applies but you may want to pick up a long-sleeve bodysuit to keep their arms covered and comfortable.
  • Shop TOG rated Transition sleeping bags for babies

Read more: When to stop swaddling your baby

Babies + Toddlers (6, 12 months+)

  • Babies that are on the move and toddlers tend to move around a lot in their sleep (and are notorious blanket-kickers). A sleep bag or footed sleep bag that stays in place, keeps them covered all night without the worry of blankets coming loose or tangled. Hello peace of mind! Our On The Move range comes in the same TOG ratings, just in bigger sizes.
  • Shop TOG rated sleeping bags and footed sleep bags

How to Tell if Your Baby is Too Hot or Too Cold

Even with the right TOG, it's good to know the signs that your baby might need an adjustment.

The neck/chest check

Slide your hand down the back of baby's neck or onto their chest. It should feel comfortably warm, not hot or clammy, and not cold. This tells you more than checking their hands or feet, which tend to run cooler naturally.

Read more: Signs your baby is too hot or too cold while sleeping

Remember: You know your baby best. These are guidelines to help but trust your instincts. If something doesn't feel right, check and adjust.

How We Test Our TOG Ratings

Published TOG ratings should be considered in conjunction with our specific clothing guides (found online and on pack) and are from test results that we believe reflect the appropriate TOG when used in conjunction with our clothing guides.

  • Test methods are EN ISO 11092, ASTM 1291 (modified to the same parameters as EN ISO 11092) and ISO 5085-1.

We believe that our TOG ratings, together with our clothing guides, help parents and carers make the best decision on how to dress their child at different room temperatures.

We also provide guidance on how the parent or carer can check if the child is too hot or too cold. This is important in empowering the parent or carer to decide what is best for their child. All children are different.

The number of clothing layers required may vary according to a child's health, their physiology, the room temperature, the outside temperature and other factors. The care-giver must determine what is suitable. We do not provide medical advice.

Frequently Asked Questions

Sleep Bag vs Swaddle: Do TOG Ratings Change?

Nope! A 1.0 TOG swaddle provides the same warmth as a 1.0 TOG sleep bag. The TOG measurement is based on the fabric's insulation, and each product is tested in its specific style, shape and size. So when you're transitioning from swaddle to transition bag to sleep bag, you don't need to change your TOG unless your room temperature has changed. Just match it to the room as usual and follow your dressing guide for layering.

Can I layer bags to increase the warmth?

No. Layering one sleep bag over another is not recommended. The TOG ratings are designed to provide the right level of warmth on their own. Doubling up can lead to overheating, which is a safety risk. Instead, choose the correct single TOG for your room temperature and adjust what baby wears underneath.

What do babies wear underneath a sleep bag or swaddle?

It depends on the TOG rating and your room temperature. As a general guide, a bodysuit, babygrow, vest or pyjamas are worn under a sleep bag or swaddle. Always check the clothing guide on your product's packaging for specific recommendations.

Do I still need to swaddle on top or underneath a TOG rated swaddle?

Nope! Our TOG rated swaddles replace the need for extra blankets or wrapping. It's a one and done sort of situation. Less layers, less stress!

Do I still need to use a blanket?

No. For babies under 12 months, loose blankets are not recommended as part of safer sleep guidelines and for older babies, blankets often come with a range of challenges. They can be kicked off and the development might not be there yet to be able to put it back on easily. Cue many night disturbances. A TOG-rated sleep bag or swaddle is like a wearable blanket and replaces the need for blankets entirely. They provide more consistent, predictable warmth and stay put so no middle-of-the-night tuck-ins needed.

Do I have to use a TOG-rated swaddle or sleep bag?

You don't have to, but it makes life a lot easier. A TOG-rated product takes the guesswork out of dressing your baby for sleep. Without one, it can be tricky to know whether your baby is warm enough (or too warm). Plus, sleep bags and swaddles are often recommended over loose blankets as part of safer sleep guidelines as they reduce the need for loose layers in the sleep space.

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