How to Dress a Baby for Sleep

Forget rocket science, neurosurgery, and clinical psychology; raising a baby is one of the most complex (yet rewarding) undertakings humans experience. As any parent will testify, feeding, nurturing, and caring for a tiny person is a blizzard of guesswork, trial, and error.

Yet, one of the more convoluted times comes not when they’re awake but when they're asleep. When the lights dim, the lullabies hum, and you’re left wondering: Is my baby too warm, too cool, or just right? Should I add more clothes, or should I remove one of the 10 layers already added? The questions and worries quickly pile up, and it's easy for parents to become tightly wound balls of nerves and doubt. 

Why Dressing Your Baby Correctly Matters for Sleep

How your baby is dressed at bedtime can make a world of difference, not just for comfort but also for safety and sleep quality. Babies can’t regulate their body temperature as easily as adults, which means the wrong layers (or too many of them) can quickly lead to overheating or chills. 

According to the American Academy of Pediatrics (AAP), a safe sleep environment means keeping your baby’s sleep space clear of loose blankets, pillows, or toys, and ensuring they don’t overheat. The right sleepwear helps achieve both: no need for blankets, and fabrics that breathe and insulate just enough for the room temperature.

That’s where materials like TENCEL™ Lyocell are worth their weight in gold. Soft, breathable, and naturally temperature-regulating, this eco-friendly fiber helps keep your baby cozy in the cold and cool when it’s warm.

Understanding TOG Ratings

What on Earth is a TOG? We're glad you asked. TOG stands for Thermal Overall Grade, a simple way to measure how warm (or cool) a piece of sleepwear will keep your baby. In simple terms: the higher the TOG, the warmer the sleepwear. 

Here’s an easy breakdown to help:

TOG	Room Temperature	What to Wear
0.5 TOG	24–27°C (75–81°F)	Diaper or short-sleeved onesie
1.0 TOG	23–24°C (72–75°F)	Long-sleeved onesie
1.5 TOG	20–22°C (68–72°F)	Short-sleeved under long-sleeved onesie
2.5 TOG	17–19°C (64–68°F)	Footed pajamas

Not sure which TOG fits your baby best? Take our quick and easy Sleep Bag Quiz to find the perfect match for your nursery setup and season.

What’s the Ideal Room Temperature for Babies to Sleep In?

Just like Goldilocks, who went to great lengths to find what was ‘just right’, babies have an optimal room temperature when they're sleeping that typically hovers between 20–22°C (68–72°F)—cool enough to prevent overheating but warm enough for cozy rest.

Here are a few simple ways to keep your baby’s sleep space perfectly balanced:

• Use a room thermometer: Don't guess. This isn't throwing a bunch of ingredients into a pan and hoping for the best—a simple digital thermometer helps you know the actual temperature.
• Skip space heaters or direct fans: Keep the room well-ventilated with consistent air flow.
• Dress for the environment, not the season: A warm nursery in winter still calls for lighter layers, while a cooler room in summer may need a higher TOG.
• Choose breathable fabrics: Natural fibers like TENCEL™ Lyocell help regulate body heat and wick away moisture, so your little one stays dry and comfortable through every sleep cycle.

How to Properly Dress a Baby for Sleep

Babies' bodies are evolving at a stunning pace, which means you must keep up with the changes. The way you dress a newborn for sleep is quite different from how you dress a 9-month-old.

Here’s how to dress your little one for dreamland, age by age:

Newborns (0–3 months)

Newborns love to feel snug and secure, but this is especially true between birth and around 3 months old when they are trying to adjust to being in the real world after 9 months of snuggle time in the mother's womb. 

Choose a lightweight, breathable option made from TENCEL™ Lyocell, which helps regulate temperature naturally so your baby doesn’t overheat.

What to use:

• A snug, hip-healthy swaddle or transitional sleep bag
• 0.5 TOG for warm rooms (24–27°C / 75–81°F)
• 1.0 TOG for moderate rooms (23–24°C / 72–75°F)

Pro tip: Avoid hats, blankets, or loose layers in the crib—babies should sleep on their back on a firm, flat surface with no extra bedding. 

Explore Loulou Lollipop’s Sleep Swaddle Collection for cozy, breathable early-weeks options.

Infants (3–6 months)

Say goodbye to that swaddled newborn and hello to the prince or princess of the roller derby. Once your child starts rolling around the crib or bed, you need to switch out the swaddle for the sleep bag, which is a safe, blanket-free way to keep your baby warm without restricting movement. Look for one that fits snugly around the neck and armholes so it can’t ride up.

What to use:

• 1.0–1.5 TOG for most rooms (20–24°C / 68–75°F).
• Add a short- or long-sleeved onesie underneath, depending on the temperature.
• Always check your baby’s chest and tummy for warmth—not their hands or feet.

Pro tip: Loulou Lollipop’s TENCEL™ Lyocell Sleep Bags are buttery-soft, sustainable, and temperature-balancing so that you can use them comfortably year-round.

Older Babies & Toddlers (6+ months)

It's now time for crawling, pulling up, walking, and perhaps even the odd acrobatic endeavor. That’s when a sleep suit (a wearable blanket with legs) can be a game-changer. It keeps your little one warm and covered while letting them move safely around the crib or during early morning play.

What to use:

• 1.5–2.5 TOG depending on room temperature
• Footed pajamas or a long-sleeved onesie underneath
• Choose soft, stretchy fabrics that breathe and move with your child

Pro tip: For cooler nights, our 2.5 TOG TENCEL™ Waffle Sleep Suit is a cozy favorite—snuggly yet breathable, and designed for little dreamers who never stop moving.

Baby Sleepwear for the Seasons

Now that we have covered the three stages of your baby's sleep development, let's take a look at the seasonal changes. Whether it’s a sweltering July night or a frosty January morning, dressing your little one for the season is all about balance: keeping them warm enough to sleep soundly, yet cool enough to stay safe and comfortable.

Summer (Warm Weather)

When temperatures soar, lightweight layers are your best friend. Stick with breathable, moisture-wicking fabrics like TENCEL™ Lyocell, which help prevent overheating while feeling silky-soft against baby’s skin.

Top Tips:

• 0.5 TOG muslin or Loulou Lollipop TENCEL™ Lyocell Sleep Bag
• Short-sleeved onesie or just a diaper underneath
• Keep room temperature between 24–27°C (75–81°F)
• Avoid fans blowing directly on the baby 

Fall & Spring (Transitional Weather)

Fall and spring can be a mixed bag, so you need something that has a little of everything. 

Top Tips:

• 1.0–1.5 TOG Loulou Lollipop TENCEL™ Lyocell Sleep Bag
• Short-sleeved onesie underneath (add long sleeves if cooler)
• Ideal room temperature: 20–23°C (68–73°F)

Winter (Cool Weather)

It can be tempting to pile on the layers when temperatures drop, but babies simply need a snug sleep suit or something similar. Humans, including the smallest versions, do surprisingly well when sleeping in colder environments.

Top Tips:

• 2.5 TOG TENCEL™ Waffle Sleep Suit, sleeper, or sleep bag
• Footed pajamas or a long-sleeved onesie underneath
• Keep the nursery around 17–19°C (64–68°F)
• Your baby’s chest and tummy should feel warm and dry, not sweaty. If you notice dampness, try removing a layer or lowering the room temperature.

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

Even with the perfect sleeping accessory, it's natural for parents to second-guess and creep into the nursery occasionally to check on their baby's temperature. Here's how to check. 

• Chest and tummy: Should feel warm and dry, not hot or sweaty.
• Back of the neck: A good indicator of body heat.
• Hands and feet: May feel cooler, but that's normal.

Here are some signs your baby might be too hot:

• Flushed cheeks or a sweaty chest
• Damp hair or clammy skin
• Rapid breathing
• Acting unusually fussy or lethargic

If you notice these signs, remove a layer, lower the room temperature, or switch to a lower TOG sleep bag.

And some signs they may be too cold:

• Cool chest or tummy (not just hands or feet—those can be cooler and still normal)
• Bluish lips or fingertips
• Frequent waking or difficulty settling back to sleep

If you notice any of the above, add a light layer underneath or move to a higher TOG sleep bag to warm things up

Frequently Asked Questions

What Are Signs A Baby Is Too Cold at Night?

If your baby’s chest or tummy feels cool to the touch, that’s your first sign they might need an extra layer or a higher TOG sleep bag. You may also notice that their hands and feet are very cold, or that they wake more often during the night.

Do Babies Wake Up if They Are Cold?

Yes, they often do. A chilly baby may stir, fuss, or cry more frequently through the night because discomfort disrupts its sleep cycles. The fix doesn’t have to be complicated: add a soft layer or move up one TOG level.

Is It Better for a Baby to Be Cooler or Warmer at Night?

It’s safer for your baby to be slightly cool rather than too warm. Overheating can increase the risk of unsafe sleep conditions, according to the American Academy of Pediatrics, while being a bit cool may simply cause a brief wake-up or a signal for more warmth. Aim for a room temperature between 20–22°C (68–72°F)

Smart Sleep Choices Support Your Baby’s Safety and Comfort

Who knew it was so complex? Yes, there's a lot to learn and keep track of, but if you're new to this, you'll soon get the hang of it. It all boils down to a few key points. Keep the nursery at a comfortable 20–22°C (68–72°F), choose breathable layers, let TOG ratings guide you, and lean towards being cooler rather than warmer. 

It's not about piling on layers of blankets, which can actually become dangerous; it’s about finding the right balance of warmth, breathability, and softness. With TENCEL™ Lyocell fabrics and thoughtfully designed features, every Loulou Lollipop sleep essential helps your little one stay cozy, comfortable, and safe—from their first swaddle to their very first sleep suit. Each piece is ASTM, CPSC, and CPSIA certified, ensuring that your baby’s bedtime routine is built on safety and quality that lasts. Because when your baby sleeps better, the whole family does too.