As new parents, maybe you’ve found yourselves wondering and worrying if your baby is too hot or too cold, especially when they’re sleeping. And this is something that’s important to monitor, since babies can’t regulate their own body temperatures like adults.

Since winter is almost upon us, keeping your little one warm is going to be a major concern. Thankfully, the TOG (Thermal Overall Grade) rating is here to make your life easier.

We’ve put together a guide to help you understand this universal rating system and how it will help your baby’s temperature stay just right, Goldilocks-style.

What is the TOG rating?

TOG is a unit of heat measurement created in Britain that helps you determine how well a fabric will insulate your little one.

TOG is useful because you can’t always tell how warm a fabric would be just by touching it. The TOG rating is not only based on how thick the fabric is, but the material type, how much heat it retains, and the amount of warmth it provides.

Basically, the higher the TOG rating, the more insulated and warmer the fabric. If the material has a lower TOG rating, it means that it’s made from a cooler, more breathable material.

According to AAP, your little one’s sleeping space should be clear of blankets and loose clothes to reduce the risk of suffocation. TOG-rated wearable blankets and sleep bags keep babies warm without the risk that blankets pose. They help standardize your baby’s sleepwear, making it easier to control and monitor their sleep temperature.

Why is the TOG rating important?

When your little one is in the womb, their body temperature is regulated by that environment. After they are born, they keep themselves warm through their body fat. But this method consumes a lot of their energy, making them more tired. 

Babies also lose body heat rapidly—four times faster than adults. Since premature babies and babies born with low weight have low body fat, they struggle more with regulating their body temperature. 

Another interesting fact is that although babies can absorb heat very well, they don’t generate it easily. Babies are also more sensitive to temperature changes than adults. That’s why you must be attentive to their clothing and how much heat it’s going to retain.

Since overheating is a leading cause of Sudden Infant Death Syndrome (SIDS) in babies, TOG ratings were introduced to sleep sacks, swaddles, and baby clothes to improve baby sleep safety. Another fabulous benefit? When babies are comfortable, they sleep longer, and that’s good news for everyone in the family. 

The TOG ratings, demystified

TOG ratings vary based on how much heat the material can retain. For example, if it’s summer, you’ll need a material with a lower TOG rating. Similarly, if it’s super cold, you’ll need a material with a high TOG rating. Here’s a quick breakdown.

1. Fairly warm room or summery weather (75 to 81°F)

0.5 TOG rating is the lowest, and best used if your baby is sleeping in a warm room or summery climate. It’s perfect for a room temperature of 75 to 81°F. If you’re using a 0.5 TOG sleep bag, your little one might only need a short-sleeved bodysuit.

2. Moderately warm room or slightly cooler summer weather (72 to 75°F)

A 1.0 TOG rating will be best suited for rooms with temperatures of 72 to 75°F. This is around the time when you might start adding an additional layer for trips outside.

3. Moderately cool room or mild fall temperatures (68 to 72°F)

Any sleep sack of this rating is suitable for a room temperature of 68 to 72°F. You can pair this with a cotton bodysuit.

4. Cooler room or crisp fall temperatures

Sleep sacks with a 2.5 TOG rating will keep your baby warm in the colder months when the temperatures are between 61 and 68 Fahrenheit.  Depending on how cool it is, then you can add additional pieces like leggings and a long-sleeve onesie.

Is a 2.5 TOG sleep sack too warm?

A 2.5 TOG sleep sack is ideal for winter months when the temperatures are between 61 to 68 Fahrenheit (16 to 20 degrees Celsius).  

5. Chilly temperatures

These sleeping bags are best suited for those chilly times—think drafty rooms or cold winter days. A 3.5 TOG rating is ideal for room temperature under 57 degrees Fahrenheit. You may want to add layers like a bodysuit, fleece leggings, or footed pajamas.

TOG chart

How to pick the right TOG rating for my baby?

The above table can be helpful in picking the right TOG rating for your little one. That said, every baby is unique.

While some babies naturally feel warmer than others, some feel colder. Some important questions to ask yourself before deciding on the TOG rating would be things like:

• Does my baby get cold easily? 
• Do they overheat easily? 
• Or do they sweat when they sleep even when it’s not that hot?

The TOG rating and clothing that works the best for your baby will be based on their typical sleeping temperature. For that, you should recognize the signs when your baby is too hot or cold.

If your baby is too hot, they will have damp hair, red ears and cheeks, a sweaty back and chest, and heavy breathing, among other things. Check the nape of your baby’s neck or their core to gauge if they are too cold, not their hands and feet, as the extremities tend to get chilly first. When in doubt, follow your instincts since you know your baby best.