From Pajamas to Sleep Sacks: How to Dress A Baby For Sleep

Baby sleeping safely and comfortably in a Woolino 4 Season® sleep sack.

4 Season® Ultimate Baby Sleep Bag, Merino Wool, 2 Months - 2 Years, Sheep - $109.00

Choosing the right sleepwear for your little one is crucial for their comfort and safety. It's important to consider both their temperature and their well-being when selecting nightwear that is breathable, snug, and cozy. 

And of course, we all want our babies to look adorable while they sleep, so finding attractive options is a bonus. Luckily, there are sleepwear choices that meet both practical and aesthetic criteria.

In this article, we’ll take a look at how to dress your baby for sleep, covering clothing safety tips, varying factors to consider – including age and the changing seasons – and end off by suggesting the best types of clothes that you should be wrapping your bundle of joy in. 

What Should a Baby Wear to Sleep?

There are two main practical factors to consider: comfort and temperature.

Achieving comfort is relatively easy. Opt for soft, breathable fabrics that won't irritate your baby's delicate skin. Many parents prefer organic and natural fabrics like wool and cotton, as they limit exposure to chemicals and are readily available.

Choose clothing items that are well-fitted but not tight. This not only enhances comfort but also ensures safety, as we'll discuss further below. In the early days, gowns or one-piece suits are popular choices, with parents transitioning to pajamas or sleep sacks as their baby grows.

Temperature regulation can be more challenging. While it's natural for parents to worry about their babies feeling cold at night, overheating is actually a greater concern. To dress your baby appropriately for sleep, it's important to be mindful of potential suffocation and overheating hazards posed by loose blankets, thick clothes, and hats.

In most cases, it's best to dress your baby in several lightweight layers that can be adjusted according to the room temperature. Comfortable bodysuits are a great starting point. The Sleep Foundation suggests adding one additional layer of clothing compared to what an adult would need to be comfortable in the room.

Alternatively, you can add a cozy wool swaddle. These will help your baby to stay in a safe sleeping position on their back and should reduce the risk of them overheating. Layers of clothing can be removed when the temperatures rise and added when they fall.

By considering comfort and temperature regulation, using soft and breathable fabrics, and opting for lightweight layers, you can ensure your baby sleeps comfortably and safely.

Sleeping Safety Tips When Dressing Your Baby for Sleep 

When it comes to baby sleepwear, safety is of utmost importance, especially for newborns. Consider the following tips to ensure your baby sleeps safely:

  • Dress your baby in clothing that is snug but not tight. This allows for comfortable movement while keeping them secure.
  • Opt for soft, merino wool footie pajamas, which are a great option for slightly older babies. The natural properties of merino wool helps regulate body temperature and provide comfort.
  • Adding a hat to your baby's sleepwear can increase the risk of overheating. It's best to avoid hats during sleep to prevent discomfort and potential overheating.
  • Loose blankets in your baby's crib pose a suffocation hazard. It's important to refrain from using them. Instead, opt for safer alternatives such as sleep sacks or wearable blankets.
  • Follow the guidelines provided by the American Academy of Pediatrics (AAP) for safe sleep practices. This includes using a firm mattress and fitted sheets in your baby's crib.

By prioritizing safety, dressing your baby appropriately for sleep, and adhering to safe sleep recommendations, you can provide a secure sleep environment for your little one.

Baby sleeping on back in crib wearing a Woolino 4 Season® Basic Baby Sleep Bag

4 Season® Basic Baby Sleeping Bag, Merino Wool, Birch Gray

Factors to Consider When Choosing Baby Sleepwear

Depending on a number of ever-changing factors, your baby's sleep attire will change over time. Let's explore these factors:


The sleep attire for a newborn differs significantly from that of an infant or a toddler. Newborns are typically dressed in gowns for easy diaper changes. 

Swaddling can be done but should be discontinued once the baby starts attempting to roll over. When swaddling, ensure it is firm around the chest but reasonably loose around the hips and legs, and always fasten the blanket securely to prevent fabric from covering the baby's face.

After the age of 12 months, it is safe for a baby to have a blanket, but younger infants should be dressed in a comfortable sleep sack. 

Sleep sacks provide warmth, safety, security, and support without the risks associated with blankets. As your baby grows older, a sleep outfit consisting of thin layers, as described earlier, is appropriate. Consider transitioning from gowns to onesies and eventually to two-piece pajama sets.

Season & Temperature

The temperature and weather play a significant role in determining how to dress your baby. 

In colder weather, opt for multiple thin layers rather than thicker clothing. Footed onesies and sleep sacks are suitable for fall and winter, with merino wool being an excellent choice due to its temperature-regulating properties. Consider merino wool socks to keep your baby's toes warm.

In spring and summer, opt for short-sleeved bodysuits and footless suits for warmer nights. Lightweight sleeping sacks and breathable fabrics are ideal choices to ensure your baby doesn't overheat.

Clothing Fit

Regardless of age, your baby's sleepwear should be comfortable yet snug. This reduces the risk of suffocation and promotes overall comfort. Some babies prefer swaddling, while others enjoy the flexibility of a sleep sack. Avoid loose-fitting sleepwear that could cover the face. If swaddling, ensure the baby can still move their hips for healthy development.

Room Temperature

The ambient temperature of the room is crucial when selecting sleepwear for newborns or older babies. 

Keep the room temperature between 68 and 72 degrees Fahrenheit and avoid adding loose blankets to the crib unless your baby is over 12 months old. Adjust your baby's layers accordingly if the room is warmer or cooler within this recommended range.

Personal Preference

It’s really important that as a parent, you feel sure your infant is comfortable and warm at night. You will probably have some personal preferences that affect how you choose your baby’s sleeping outfit, and that’s fine.

As long as you follow the safety guidelines, choose whatever sleepwear seems right to you.

Cute baby feet wearing blue Woolino Merino Wool Socks

Wool Socks, Baby and Toddler, Blue - $17.00

Best Types of Clothing for Baby Sleep

As discussed above, there are a lot of different options when it comes to choosing a newborn sleeping outfit, or sleepwear for an older child. Sleep sacks, blankets, footed pajamas, onesies, socks, mittens, swaddles, and hats all have their place in sleepwear. 

Sleep Sacks

A sleep sack is an excellent choice for your baby's sleepwear. It provides a safe alternative to loose blankets and keeps your little one snug without the risk of entanglement. 

A sleep sack provides a diverse clothing option, commonly used by parents for newborns and older babies. If your infant doesn’t like being swaddled, or if you’d prefer an easier option for keeping them cozy and supported, a sleep sack is a great choice.

Woolino's sleep sacks are specifically designed with your baby's comfort in mind. They feature temperature regulation properties, ensuring your baby stays cool in hot weather and cozy in colder temperatures. These breathable and moisture-wicking sleep sacks offer both safety and comfort, allowing your baby to sleep peacefully. 

Discover the full range of Woolino's sleep sacks here.


Once your baby reaches 12 months of age, it's generally safe to introduce a loose blanket into the crib. 

Opt for a lightweight and small blanket to prevent tangling. Woolino offers super soft merino wool blankets perfect for toddlers. These blankets provide year-round temperature regulation, hypoallergenic properties, and luxurious softness, ensuring your child's comfort and well-being.

Footed Pajamas

Footed pajamas ensure your little one has warm feet at night, and mean that they can move around easily when they are up and about. 

They’re less fussy than trying to put socks on your baby’s feet, and there’s no risk of them getting kicked off.

Cotton, bamboo and merino wool footed pajamas – in particular – offer fantastic breathability, comfort, and moisture-wicking properties.


Onesies are good for children because they stay on (unlike two-piece pajamas) and they provide warmth and coziness. They also make it easy to change the baby’s diaper, and they tend to offer a snug, comfortable fit. 

There are lots of different styles, including snap-up and zip-up options. Some parents prefer zips, but they have more of a tendency to break and get stuck, which leads others to stick with snaps. Either should be safe for your child.


Socks can provide added warmth and security for your baby's feet, particularly if they are not wearing footed sleepwear. However, be cautious with small infants as they may kick off socks, which could potentially become a choking hazard. 

If the weather warrants it, you can consider using Woolino's specially designed wool socks to keep your baby's toes warm which have been specially designed for chilly toes and come in sizes from birth to 6 years old.


Mittens can be a suitable option for newborns during sleep. However, they should only be worn for a short period as babies tend to pull them off. Choose mittens without any choking hazards such as ribbons or buttons. Look for natural fibers like bamboo or soft cotton for breathability and comfort.

One thing to note, bamboo does require a lot of processing to become fabric, with some parents opting for more organic materials as a result of the chemicals used in the manufacturing process.


Swaddles are an important part of a newborn's sleeping outfit. They help reduce the startle reflex and provide a sense of security, promoting better sleep for both the baby and parents.

The proper swaddling technique is essential for safe and effective swaddling, which we cover below:

  1. Arrange your blanket on a flat surface, in a diamond shape, with the bottom of the diamond pointing towards you.
  2. Fold down the top edge of the blanket to form a triangle.
  3. Place your baby on the blanket with their feet towards you, ensuring their shoulders are just below the fold of the blanket.
  4. Gently bend your baby's right arm and tuck it against their side.
  5. Tuck the right side of the blanket up over the arm and body, and wrap it around to tuck underneath the baby. Leave the left arm free for now.
  6. Fold the bottom of the blanket up over the baby's feet.
  7. Bend your baby's left arm and bring the left side of the blanket across the arm and over the body.

Ensure the swaddle is snug but not too tight, providing support to the hips while allowing some movement. If preferred, you can swaddle with the arms free. Alternatively, you can opt for swaddles with built-in zippers or Velcro for convenience.

When choosing a blanket for swaddling, opt for lightweight options and avoid thick or heavy blankets.


Hats can keep your little one warm on cold evenings, but the AAP says you should never leave your infant to sleep with a hat on. Hats increase the risk of overheating and will often make your baby too warm.

If you are going to use a hat for your child in the evening, opt for a lightweight, soft, and comfortable hat. Cotton or merino wool might be good options. No matter how light the hat is, remove it before settling your child to sleep.

Happy baby laying on lambskin rug dressed in Woolino merino wool Bodysuit and Footed Pants

Baby Bodysuit, Long Sleeve, Merino Wool, Beige - $35.99Baby Footed Pants, Merino Wool, Beige - $32.99


When it comes to dressing your baby for sleep, prioritizing safety, comfort, and temperature regulation is crucial. While aesthetics can be important, it's essential to prioritize functionality.

Opt for sleepwear made from breathable and moisture-wicking fabrics. These fabrics help keep your child comfortable and prevent overheating during the night. Look for sleepwear that has temperature-regulation properties, such as Woolino's sleep sacks, which are designed to keep your baby cool in hot weather and warm in cold weather.

Avoid loose clothing or blankets, especially for young babies. Loose blankets should be avoided until your child is at least 12 months old. Instead, opt for sleep sacks or wearable blankets that provide a snug and secure fit. Layering multiple lightweight garments can also help keep your baby warm without the need for loose blankets.


How do I know if my baby is too hot or too cold during sleep?

It’s usually fairly easy to tell if your infant is too warm. Look out for:

  • Flushed skin
  • Fast breathing
  • Sweaty face
  • Damp hair
  • Rapid heartbeat
  • Restlessness
  • Heat rash
  • Lethargy/unresponsiveness

If you think your baby is too cold, touch their core body (chest, neck), rather than their extremities. Your baby can have cold hands and feet without being too cold. You can tell if your baby is too cold by looking out for:

  • Blotchy skin
  • Overly sleepy/lethargic
  • Constant waking or difficulty falling asleep

If you think your baby is the wrong temperature, adjust their clothing, but don’t add a hat, loose blanket, hot water bottle, etc. Avoid having a heater or a fan running in your baby’s room while they are sleeping if possible. Add or remove layers to better control their temperature.

When can I transition my baby out of swaddling?

A baby can be swaddled until they begin trying to roll over on their own. At this point, they need their arms free so that they can support themselves, and a swaddle becomes dangerous. You should also stop swaddling if your baby starts resisting it. The transition usually occurs around 2-3 months old.

You may want to start the transition before your baby shows active signs of rolling over. You can either transition all at once and use other familiar methods (such as patting) to soothe your baby, or transition slowly. Only transition slowly if your baby is not yet trying to roll over. If they are, stop swaddling immediately.

To go slowly, try just removing one arm at first (if the type of swaddle you have allows for this). You can also try removing the swaddle when you first put your baby down for the night, but putting it back on when they first wake up, or if they won’t settle.

Gradually increase the sleeping period without the swaddle, and then start reducing swaddling at nap time too.

A sleep sack can be a good alternative to a swaddle as your baby grows. It will offer them a sense of security and comfort, but is looser, and safe for children who can roll over.

What should I consider when choosing the right sleep sack for my baby?

There are quite a few things to think about. You need to consider the size, first and foremost. Sleep sacks usually come with an estimated size or age range. Some can be adjusted to grow with your baby, while others are a fixed size. Make sure your baby has room to move around, but don’t get a sack that’s loose enough to be kicked off.

You should also think about the TOG rating. Different ratings are suitable for different temperatures. High TOG ratings are warmer than low ones. You can use a chart to determine which TOG ratings are right for which temperatures.

Material is also important. Opt for soft, comfortable, breathable fabrics. Moisture-wicking properties are a big advantage because they’ll keep your little one dry and comfortable all night.

Do babies cry if they are too hot or too cold?

Don’t depend too heavily on your little one crying to tell you if they are the wrong temperature. Although many babies will exhibit restless behavior if they are the wrong temperature, a sleeping infant may not wake up enough to do so.

Always check the ambient temperature of the room before setting your baby down for the night, and avoid over-dressing them, especially in thick, insulating clothing. Remember, too cold is safer than too hot.