Does A Baby Need A Sleep Sack in Summer? Decoding Seasonal Sleepwear

Baby lying in crib wearing a Woolino 4 Season® Ultimate Baby Sleep Bag in Sun print

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

You may already be aware that the way you choose to dress your infant for bed makes a huge difference to how comfortable and even how safe your child is overnight. Wearing the wrong clothing could result in your baby getting too hot at night, which has been associated with SIDS, or too cold, which can also be dangerous.

Your baby is not likely to sleep well if they are too warm at night, so it’s very important to find suitable sleepwear for them. You might be wondering, does a baby need a sleep sack in summer? Can you just leave them in their diaper?

A baby doesn’t have to have a sleep sack in the summer, but using one can have several big advantages, and many parents do have sleep sacks that are suitable for the hotter months. A summer sleep sack will help to keep your little one in a safe position in their bed and will reduce the risk of them getting too cold if the temperature drops overnight.

With that in mind, let’s learn more about the importance of choosing the correct sleepwear for summer!

The Basics of Baby Sleepwear

Many parents use a sleep sack for summer, due to the numerous advantages. If you aren’t familiar with a sleep sack, it is essentially a baby-sized sleeping bag, but it is designed to be snug and cozy around the baby’s torso, with a loose pouch of fabric around the baby’s lower body and legs. To find out more about sleep sacks, take a look at our dedicated guide “What is a Sleep Sack”.

So, what are the main sleep sack benefits you should be aware of? There are quite a few! Firstly, a lightweight sleep sack will help to regulate your child’s temperature throughout the night. Ambient temperatures often go down during the night, and there is a risk that your baby will get cold in the early hours if they are only wearing a diaper.

Furthermore, a sleep sack will help your child to feel secure, because it offers a similar sensation to being swaddled. They will feel safe and are more likely to stay on their back in a comfortable sleeping position. It is thought that using a sleep sack could even reduce the risk of SIDS.

A sleep sack will stop your child from getting up in the night and trying to climb out of their crib, too. Since this poses several risks, including slipping and falling out of the crib or bumping their head on something, this is another major safety benefit. Sleep sacks will give you peace of mind that your little one will stay lying down, keeping them safe throughout the night.

There are, of course, a lot of things to think about when it comes to choosing summer sleepwear for your infant. One of the most important ones is the room temperature. If the room is around or above 72 degrees F, your child is at much greater risk of overheating, so you will need to choose very lightweight clothing accordingly.

The age of your baby also makes a big difference. Once your child is over a year old, you can add a cozy blanket to their bed. This will keep them warm and secure, and they’ll generally have enough motor control by this point to push it away or pull it over them according to whether they feel hot or cold. Younger babies should not be given blankets, as these pose a suffocation risk, so a sleep sack is generally considered the safest option for them.

The kind of material that the nightwear is made of makes a big difference to what the infant wears, too. Look out for light, breathable fabrics that are suitable in the summer months.

Whatever sleepwear you choose, you should pay attention to the Thermal Overall Grade (TOG rating). This rating tells you what temperature the sleepwear is suitable for, and it’s key to choosing the right bedding for your baby all year round!

Baby sleeping on back wearing a Woolino 4 Season® Ultimate Baby Sleep Bag in Whales print

Is a Sleep Sack Necessary in Summer?

You don’t have to have a baby sleeping sack in the summer, but many parents find that it’s very helpful. You can dress your child in just their diaper and a sleep sack, or add one layer underneath. There are quite a few benefits to this, including:

  • Your baby will stay at a consistent temperature throughout the night, and you don’t need to worry about them getting cold when the temperature drops (which is the time when parents are most likely to be asleep themselves and not watching their infant as closely)
  • Your baby is kept in a safe position on their back throughout the night. Older infants won’t be able to climb out of their cribs, risking possible falls
  • Your little one will feel comfortable and secure, encased in a warm – but non-restrictive –  bag that creates a micro-environment around their body

Of course, there can be drawbacks to using a sleep sack when it’s hot. The most obvious is that it can cause overheating, especially if you choose the wrong material. Woolino’s 4-seasons sleep sacks are made of soft merino wool, which has excellent temperature regulation properties and therefore keeps your child comfortable overnight. They’re perfect even in the summer because wool is great at regulating temperature.

However, breathable cotton sleep sacks can also make a huge difference in the summer, when your child is too hot and struggling to sleep well. Cotton is light and breathable, and ideal for summer nights.

Remember that overheating poses some serious risks to your child’s health, up to and including death. It can be as dangerous – or even more dangerous – than your baby getting too cold, so make sure you take it very seriously.

Understanding Heat Regulation in Babies

It’s important for parents to recognize that babies don’t regulate their body temperatures the same way that adults do. They have a much greater surface area relative to body weight than adults, and that means they can’t control their temperature nearly as well. Additionally, they have less motor control, and cannot shiver or dilate their blood vessels effectively (both methods older children and adults use to control temperature). 

As a parent, you need to be on the lookout for signs that your baby is getting too hot, including things like:

  • Flushed cheeks
  • Sweaty hair (but note that your baby can be too hot even if they aren’t sweaty)
  • Restlessness
  • Lethargy
  • Core body feeling too warm
  • Elevated heart rate
  • Signs of confusion
  • Refusal to wake up

Choosing breathable fabrics for your baby’s sleepwear will greatly reduce the risks of overheating. Fabrics like wool and cotton breathe very well, meaning that they allow air to pass from the wearer’s body to the outside world. This makes them much cooler in the summer, reducing the risks of overheating and making your child more comfortable. 

In addition, wool is known for its ability to absorb water. That means that if your child is sweaty, the wool will pull the water away, cooling the skin as it does so, and making your child more comfortable.

Wool and cotton are therefore both excellent fabrics for parents to consider when looking to reduce the risk of overheating and keep their little ones comfortable all year round.

Baby sleeping peacefully in a Ecolino® Basic Organic Cotton Baby Sleep Bag in Desert print

Ecolino® Basic Organic Cotton Baby Sleeping Bag, Desert - $32.99

Dressing Your Baby for Sleep in Summer

So it’s summer… and warm, you may be wondering how to dress your child at bedtime. Many parents choose to put their children in footie pajamas under their sleep sacks, but if the weather is very warm, a lightweight bodysuit will often be enough. If it’s really hot, just dressing them in their diaper and the sleep sack could be enough.

Some parents choose to forgo a sleep sack and only dress their children in pajamas. This can work but bear in mind that your little one may get cold if temperatures drop, and might become restless. Remember, don’t give your child a blanket until they are over 12 months old. 

You might also want to consider sleep sacks without sleeves, or sleep sacks that can be left open around the baby’s legs. Selecting comfortable, high-quality, and temperature-regulating bedding can be beneficial for children of all ages when it comes to getting a good night's sleep in the summer.

Make sure your baby sleeps in a room that is reasonably cool and comfortable. You can use a fan in your child’s room at night, provided it is pointing away from the bed. Keeping the curtains closed and the windows open will also help. Some parents hang damp sheets over the window so that the breeze will blow cool, damp air into the room.

Giving your baby a lukewarm (not cold!) bath before bed can help them start out at the right temperature, especially if the day has been hot. Checking in with them frequently is also a good idea; you should monitor them every 15 minutes or half an hour, and physically check their core body heat. This increases the chances of you noticing quickly if they are getting too warm.

Conclusion

As you can see, keeping an eye on your child’s temperature during summer nights is crucial, because there are some serious risks associated with overheating, including SIDS. A hot infant is likely to be miserable and will sleep poorly too – which in turn means you’ll sleep poorly.

Fortunately, there’s plenty you can do to ensure your little one stays cool. An appropriate sleeping bag and other lightweight sleepwear will help a lot. Sleep sacks are a fantastic option that provides temperature control all night long, as well as feelings of security, with most infants sleeping better in them. It’s for this reason that many parents choose them. Truly a great option for summer sleepwear. 

We hope this answers the question “Does your baby need a sleep sack in summer?”. Remember, if you’re ever concerned that your baby may be overheating or, you’re looking for additional solutions to keep your baby cool, always contact your pediatrician for guidance.

FAQs

How can I tell if my baby is too hot while sleeping in a sleep sack?

Look for signs like flushed cheeks, sweating, and restlessness. Feel your baby’s core temperature by putting your hand on their chest or the back of their neck (don’t judge by limbs or extremities). Measuring their temperature yourself is the best way to check how warm they are.

Can a sleep sack replace other forms of baby bedding during summer?

Yes, a sleep sack can be used with just a diaper; you don’t have to dress your baby in pajamas underneath. Using just a sleep sack and a diaper is a great way to keep your little one cooler when it’s really hot. Sleep sacks are generally soft and comfy enough to be worn against the skin, especially when they’re made of natural fibers like merino wool.

What should a baby wear under a sleep sack in the summer?

As long as your baby is wearing a diaper, there’s no need for any other layers beneath a sleep sack. However, you can dress your baby in a lightweight, breathable onesie or other pajamas if you think this would make them more comfortable. Regularly check whether they are getting too hot, especially if the room is warm.

How does breathable fabric in sleep sacks help prevent overheating?

Breathable fabric in sleep sacks lets hot air pass away from your child’s body, releasing it into the room. Non-breathable fabrics trap the air close to the body and increase the child’s risk of overheating. Choose things like cotton, wool, and other natural fibers to reduce this issue.

Are there specific sleep sacks designed for summer use?

Yes, there are lots of sleep sacks designed for summer use! These may have things like no sleeves, open fabric around the legs, and breathable fabric. Woolino’s cotton line is great for use in the summer, our 4-seasons options are also designed to be used throughout the year. Whatever choice you settle on, make sure you have enough sleep sacks for every season!