If you’re shopping for a baby sleep sack, you’ve probably seen the term “tog” and wondered what it means. Understanding what is tog in sleep sacks is the key to choosing the right one for your baby’s comfort and safety through every season.
Think of tog as a unit of measurement for warmth, just like thread count is for sheets. It tells you how much insulation the sleep sack fabric provides. A higher tog number means a warmer, thicker sack, while a lower tog number indicates a lighter, cooler one. Picking the correct tog helps prevent your baby from getting too hot or too cold, which is crucial for safe sleep.
What Is Tog In Sleep Sacks
Let’s break it down simply. Tog is a standard rating that measures thermal resistance. It was originally used for duvets and quilts, but it’s now the universal language for baby sleep sack warmth. The tog system gives parents a clear, comparable way to select bedding based on the room temperature.
Here’s a basic guide to what the numbers mean:
- 0.2 to 0.5 Tog: These are very lightweight, muslin or single-layer cotton sacks. They’re perfect for hot summer nights or as a wearable layer in a warm nursery.
- 1.0 Tog: A light, all-season option. Usually made of a single layer of cotton or a light microfiber, ideal for room temperatures around 74°F (23°C) and above.
- 2.0 to 2.5 Tog: The most common and versatile choice. These are medium-weight and suitable for standard room temperatures, typically between 68-72°F (20-22°C). They work for spring, fall, and cooler summer nights.
- 3.0 to 3.5 Tog: These are warm, thick sleep sacks. They’re designed for colder winter nights when the room temperature is around 61-68°F (16-20°C). They often have a plush or fleece lining.
- 4.0 Tog and above: Extra-warm sacks for very cold rooms, usually under 61°F (16°C). These are less common and should be used with caution to avoid overheating.
Why the Correct Tog Rating Matters for Safe Sleep
Getting the tog right isn’t just about comfort; it’s a major safety factor. Overheating is a known risk factor for Sudden Infant Death Syndrome (SIDS). A baby who is too hot will sleep more deeply, making it harder for them to wake up if they have trouble breathing.
Babies can’t regulate their body temperature as well as adults can. They also can’t kick off a blanket if they’re too warm. A sleep sack with the appropriate tog rating, combined with the right room temperature and clothing, acts as a safe, consistent layer of warmth.
Signs your baby might be too hot include sweating, damp hair, flushed cheeks, heat rash, or rapid breathing. If you notice these, they may need a lower tog sack or lighter clothing underneath.
How to Choose the Right Tog: A Simple Step-by-Step Guide
Follow these steps to make the perfect choice for your little one.
- Check the Room Temperature: Use a reliable room thermometer placed near the crib, away from windows and vents. Check it at night when baby sleeps.
- Match Tog to Temperature: Use a general tog chart as your starting point. Most brands provide one on their website or packaging. Here’s a common example:
- Over 75°F (24°C): 0.2 – 0.5 tog
- 71-75°F (22-24°C): 1.0 tog
- 68-72°F (20-22°C): 2.0 – 2.5 tog
- 64-68°F (18-20°C): 2.5 tog with long sleeves/pajamas
- 61-64°F (16-18°C): 3.0 – 3.5 tog
- Below 61°F (16°C): 3.5 tog+ (and consider warming the room slightly)
- Consider What’s Underneath: The tog rating assumes your baby is wearing appropriate pajamas. A 2.5 tog sack over a diaper onesie is cooler than the same sack over fleece footie pajamas. Always dress baby in light, breathable layers under the sack.
- Factor in Your Baby’s Metabolism: Some babies naturally sleep hotter or colder. Use the chart as a guide, but adjust based on your baby’s cues. A baby who often feels warm to the touch might need a lower tog than the chart suggests.
- Think About Season and Climate: If you live in a place with big temperature swings, you’ll need a collection of sacks. A 0.5 tog for heatwaves, a 2.5 tog for most of the year, and a 3.5 tog for winter is a good basic set.
Common Mistakes Parents Make With Tog Ratings
Even with the best intentions, it’s easy to make a mistake. Here’s what to avoid.
- Ignoring the Room Thermometer: Guessing the temperature is often inaccurate. Your living room might feel chilly, but the nursery could be warmer. Always measure.
- Doubling Up Sacks: Never put two sleep sacks on your baby. This can lead to dangerous overheating and restricts movement. If you need more warmth, use a higher tog sack or add a layer of clothing underneath.
- Using a Blanket with a Sack: Sleep sacks replace loose blankets. Adding a blanket on top defeats the safety purpose and adds too much warmth.
- Choosing Based on Feel Alone: The thickness of different fabrics can be misleading. A fluffy 2.5 tog microfleece might feel warmer than a 2.5 tog cotton quilted sack, but their thermal rating is the same. Trust the tog number on the label.
Dressing Your Baby Under a Sleep Sack
The tog rating works together with your baby’s clothing. A good rule is to dress your baby as you would dress yourself for the room temperature, plus one extra light layer. For most homes, this means:
- Warm Rooms (over 75°F / 24°C): A diaper alone under a 0.2-0.5 tog sack or just lightweight pajamas with no sack.
- Average Rooms (68-72°F / 20-22°C): A cotton onesie or lightweight footed pajamas under a 2.0-2.5 tog sack.
- Cool Rooms (61-68°F / 16-20°C): A long-sleeved bodysuit plus heavier cotton or fleece pajamas under a 2.5-3.5 tog sack.
Always feel your baby’s chest or back of neck to check their temperature. Hands and feet are often cooler and aren’t a good indicator.
Special Considerations: Preemies and Older Babies
Premature babies have even less body fat and struggle more with temperature regulation. They often need a higher tog sleep sack or an extra layer until they reach their due date and gain weight. Always consult your pediatrician for advice on dressing a preemie.
As babies become toddlers and move more, they might generate more body heat. An active 18-month-old might need a lower tog sack than they did at 6 months old in the same room. Keep reassessing as they grow.
Beyond Tog: Other Features to Look For in a Sleep Sack
While tog is the most important feature for warmth, other factors contribute to safety and comfort.
- Size and Fit: The sack should be snug around the neck and armholes so baby can’t slip down inside, but roomy around the body and hips for leg movement. It should not be too long; their feet should be near the bottom.
- Zipper or Snap Design: A two-way zipper that opens from the bottom makes nighttime diaper changes much easier. Some parents prefer shoulder snaps for putting the sack on over the head.
- Material: Choose natural, breathable fabrics like cotton, bamboo, or muslin. These help wick moisture and prevent overheating. Polyester fleece is warm but less breathable, so use it for lower room temperatures.
- Sleeveless Design: For safety, sleep sacks should always be sleeveless. This helps with temperature regulation and prevents overheating.
- TOG-Weighted Sacks: Some innovative sacks have removable inner layers. You can zip out a 1.0 tog liner to convert a 3.5 tog sack into a 2.5 tog sack, offering more versatility.
Frequently Asked Questions (FAQ)
What does 2.5 tog mean?
A 2.5 tog rating means the sleep sack has a medium level of thermal insulation. It’s the most popular and versatile weight, suitable for standard room temperatures around 68-72°F (20-22°C). It’s often considered an all-season option in climate-controlled homes.
Can my baby wear a sleep sack in summer?
Absolutely! You just need to choose a low-tog sack. Opt for a 0.2, 0.5, or 1.0 tog sleep sack made from a breathable material like cotton or muslin. Dress baby in just a diaper or a very light onesie underneath, and ensure the room is well-ventilated.
How many sleep sacks do I need?
It’s smart to have at least two or three. Babies can spit up or have diaper leaks at night, so having a backup is essential. A good starter collection might include one 1.0 tog, one 2.5 tog, and one 3.5 tog sack to cover different seasons. If you live in a very hot climate, add a 0.5 tog.
When should I switch tog ratings with the seasons?
Switch based on the actual temperature in your baby’s room, not the calendar. When you notice the nightly room temperature consistently rising or falling for a week or more, it’s time to switch to a more appropriate tog. Using a room thermometer takes the guesswork out of it.
Is a higher tog sleep sack safer for winter?
Not necessarily. Safety is about avoiding overheating as much as avoiding being too cold. A 4.0 tog sack in a 70°F room is dangerous. Use a higher tog sack only when the room temperature justifies it. It’s safer to use a moderately warm sack (2.5-3.5 tog) and adjust baby’s pajamas underneath if the room is chilly.
Can I use a sleep sack when my baby starts rolling?
Yes, sleep sacks are actually safer than loose blankets for rolling babies. They allow for leg movement and rolling while keeping baby covered. Ensure the sack is the correct size—not too long—so it doesn’t interfere with movement. Transitional sacks with leg holes are also available for older, mobile babies.
What should my baby wear under a 3 tog sleep sack?
For a 3.0 tog sack in a cool room (around 64-68°F / 18-20°C), dress your baby in a long-sleeved cotton bodysuit and a pair of cotton or fleece footed pajamas. Always check their core temperature to be sure your not overdressing them.
Final Tips for Sleep Sack Success
Remember, the tog system is your friend. It takes the confusion out of choosing bedding. Start with a room thermometer, use a tog chart as your guide, and always trust your baby’s cues over any rigid rule. A comfortable baby is a safer, better-sleeping baby. With the right tog sleep sack, you can both rest a little easier.