The 7 Best Sleep Sacks For Summer, According To A Pediatrician

When you put your little one to sleep on a warm night, the best sleep sacks for summer will be made with a fabric that’s cozy yet breathable for the temps. The American Academy of Pediatrics (AAP) recommends sleep sacks over loose blankets or other coverings, but not all sleep sacks are ideal for warmer weather, and, according to Dr. Florencia Segura, MD, FAAP, “it’s essential to make sure that you select an appropriate sleep sack given the ambient temperature.”

How to choose the best type of fabric

If you’re wondering how to pick the right one, it comes down to choosing a lightweight, breathable fabric that won’t cause your baby to overheat. And as Dr. Segura advises, “natural fibers such as cotton are often the best for sleepwear” in order to keep your child from getting too hot. Besides cotton, keep an eye out for silky bamboo rayon or temperature-regulating merino wool. Azlon, which is a synthetic fabric derived from soy, can also be a great option, since it’s breathable and feels like cashmere.

That said, fabric type isn’t the only factor when it comes to judging the warmth of a specific sleep sack. Keep an eye out for each sack’s Thermal Overall Grade (TOG) score, which measures the insulation of the fabric. The higher the rating, the warmer the sleep sack. Dr. Segura’s recommendation is to look out for a “sleep sack with a TOG of 1.0 or lower in the summer.” However, she adds, “If the temperature is less than room temperature (68 degrees Fahrenheit), you would want to choose a higher TOG.” When in doubt, the AAP recommends that your little one be dressed in one more layer than what you’re wearing.

How to choose the best style of sleep sack

Dr. Segura notes that sleep sacks can be especially “great for babies who have outgrown their swaddles once they have started rolling.” However, sleep sacks come in a few different styles that can grow with your child. There are even sleep sack and swaddle combinations if your baby is nearing this transition and you want to minimize the different products you need to purchase.

It’s also important to note that sleep sacks aren’t just for babies. Toddlers can also benefit from sleep sacks “to help them associate sleep as part of a bedtime routine,” explains Dr. Segura, adding that these “can also help them prevent throwing one leg over the crib rail, keeping them in the bed for a little bit longer!” Sleep sacks made for toddlers are designed to allow some movement in the legs by having the feet pop out at the bottom. Whatever style you pick, just make sure to follow manufacturer recommendations for the correct age and weight range in order to achieve the best fit.

From cotton to merino wool, for preemies to toddlers, here are the best sleep sacks to keep your child comfortable and ready to sleep in the summer months.

1. A Fan-Favorite Organic Cotton Sleep Sack

• TOG rating: 0.5 or 1.5
• Recommended age: 0 to 18 months, depending on size

With more than 22,000 reviews and a stellar 4.8-star rating overall, it’s easy to see that this Burt’s Bees sleep sack is a popular choice. It’s made of organic cotton that hasn’t been treated with synthetic chemicals like pesticides or flame-retardants, and even boasts a Global Organic Textile (GOTS) certification. The breathable fabric has a low TOG of 0.5, making it ideal for steamy summer months. One reviewer reports: “This adds just enough of a layer to keep baby cozy and feeling more ‘ready for sleep.’” The zipper closes from top to bottom so it’s away from baby’s face and makes late-night diaper changes a little easier, and the zipper also snaps in place so your little one won’t kick it open in their sleep. Plus, it comes in tons of cute patterns and is machine washable to boot.

The brand recommends buying this sleep sack in a size small for babies up to 6 months of age, a size medium for babies 6 to 12 months in age, and a size large for babies 12 to 18 months in age. If you need a slightly thicker sleep sack, Burt’s Bees also sells sleep sacks with TOG of 1.5.

Helpful Amazon review: “My 6 month old outgrew his old transitional swaddle in length - his legs were smooshed. In this sleep sack, he has plenty of room to kick to his delight! The material is soft and not too warm, even for a Georgia summer. The larger zipper is easy to locate and use in the dark. I like the bigger arm holes too. The zipped area near the top sometimes bunches up a bit and he sometimes bites on it to soothe his gums but it’s not too bad. We love it and recommend it to other babies who are longer or need to kick. Worth the money.”

• Available sizes: Small — Large

2. A Budget-Friendly 2-Pack Of Cotton Sleep Sacks

• TOG rating: 0.5
• Recommended age: 0 to 18 months, depending on size

For any baby items, having a backup can be a lifesaver, which is why this two-pack of cotton sleep sacks is a must-have for the more than 10,000 parents who have awarded it five stars on Amazon. They’re a great deal, too, since a price tag of around $25 for the pair means they’re less than $15 each. The sleep sacks are made from lightweight, breathable cotton with a low TOG of 0.5, leading multiple reviewers to rave that they’re perfect for summer nights. The convenient design features a two-way zipper for easy diaper changes, with zipper protectors keep your little one from getting irritated. They’re also machine-washable.

The sleep sacks come in four different sizes, from small (recommended for babies 0 to 6 months old) to extra-large (recommended for babies 12 to 24 months of age).

Helpful Amazon review: “These wearable blankets have been perfect for our baby transitioning out of swaddles. He is a very sweaty baby, and I love that these are thin and lightweight- perfect for summer. Also, the two-way zipper is convenient for night time diaper changes. We have had them over a month, and he wears them every night. I wash them regularly on a gentle cycle and dry them in the dryer and the zipper is still perfect, material soft, and they aren't even faded. I will definitely order again when we want to size up and would recommend them for a summer sleep sack or a sleep sack for babies who run hot.”

• Available sizes: Small — X-Large

3. A Cotton & Merino Wool Sleep Sack For All Seasons

• TOG rating: No rating provided, but the brand recommends it for for room temperatures of 63 to 77 degrees Fahrenheit
• Recommended age: 2 to 24 months

This Woolino sleep sack might sport a higher price tag, but that doesn’t mean it’s not a good deal — after all, it’s designed to be comfortable in temperatures ranging from 63 to 77 degrees Fahrenheit, making it ideal for year-round use instead of just for the summer. And, with adjustable under arm snaps, this sleep sack is good for 2 to 24 month olds, so you don’t need to upgrade every time your little one grows. That’s right — this is the only sleep sack you’ll need until your baby is about 2 years old (though you might want more than one, because, laundry).

The sleep sack is made with a GOTS-certified organic cotton outer layer and a merino wool inner layer that the brand suggests will regulate your little one’s body temperature, keeping them warm in the winter and cool in the summer. It even comes with a nursery thermometer and a dressing guide for the best way to outfit your baby underneath their sleep sack. If this sounds too good to be true, take one reviewer’s word for it. “I was worried about him wearing it in all weather,” they wrote, “but so far he's worn it in the early Spring weather when our house got to 65 at night and also in the warm summer when it was up to 80 inside some nights. Their layering guide has been really helpful.”

The design also features a two-way zipper for ease of use, plus seat belt slots so that transferring from a stroller or car seat to crib is a snap. Plus, it’s machine washable and available in 13 adorable prints.

Helpful Amazon review: “My son used this sleep sack from about 6 months until just shy of 2 years when he learned how to unzip it. It really was the perfect weight. I was worried it would be too warm during the Texas summer, but it was fine. Like anything else, it's about how you dress the baby. I wish I would have found this when my son first came out of the swaddle. I wasted so much money buying sacks in different sizes and different weights. This is one of the very few items that I do not regret spending the extra money on. It's been washed a TON and survived a few blowouts. It has held up extremely well.”

• Available size: One size only

4. A Super-Lightweight Sleep Sack For Warmer Weather

• TOG rating: 0.3
• Recommended age: 0 to 18 months, depending on size

With a TOG score of just 0.3 (the lowest on this list), this thin, breathable sleep sack is ideal for warmer temperatures — the brand recommends it for 76 to 80 degrees Fahrenheit. Made from an open-weave cotton muslin that allows for excellent air flow, it’s no wonder that reviewers report that it’s perfect for summer. One fan even raved, “This is SO lightweight and perfect for a nap with windows open.” There’s a 2-way zipper, so it can close from the top to the bottom or the bottom to the top, plus zipper guards so the zipper never gets in your baby’s way. It’s machine washable and comes in 12 prints and designs including lambs, giraffes, stars, and more.

Helpful Amazon review: “This sleep sack is perfect for warm summer nights! It's thin muslin material, but not cheap. We've had ours for a few weeks, and it's been through the wash many times already since our daughter wears it nightly. It still looks like new! The zipper tucks away so it won't bother your little one when they roll over, and it has two way zippers so you can do easy diaper changes at night. The sizing was just as I expected, and the hedgehogs are adorable!”

• Available sizes: Small (0-6 Month) — Large (12-18 Month)

5. A Sleep Sack With Long Sleeves

• TOG rating: none provided
• Recommended age: 0 to 24 months, depending on size

If you’re concerned about your baby’s comfort in an air conditioned room in the summer, you might want to consider a long-sleeved option like this sleep sack. Although there is no TOG listed, one reviewer described it as “not too thick and not too thin,” while another wrote, “I love that this sleep sack is light weight and he can wear it over his jammies without getting too hot.” The sleep sack is made of organic cotton and azlon, a soy-derived material that’s known for being soft and breathable, it has another reviewer calling it “the softest sleep sack I had found so far.”

The sack comes in over a dozen different colors and designs, all of which are machine washable. Reviewers report that these sleep sacks run small, so take that into consideration when shopping.

Helpful Amazon review: “Light weight, extremely soft and long sleeved. Perfect for summer naps when my baby is in short sleeved tops. There’s no need to fret about the ac causing my baby’s arms to be too cold!”

• Available sizes: 0 to 6 months — 12 to 24 months

6. A Bamboo & Cotton Sleep Sack For Toddlers

• TOG rating: 0.8, 1.2, or 1.5
• Recommended age: 12 months to 4 years, depending on size

When your little one starts walking, you might want a sleep sack with some mobility. If that’s the case for you, take a look at this loose-fitting sleep sack with cuffed foot holes at the bottom so toddlers can move without tripping. It’s made from a soft, breathable blend of bamboo rayon and cotton that’s quilted and padded lightly with polyester. While the padding might seem like it’s not ideal for summer, the sleep sack does have a TOG score of 0.8, with the brand recommending it for nursery temperatures between 67 and 75 degrees Fahrenheit. The sleep sack is machine washable, but the brand advises that bamboo might shrink slightly after its first wash, so select a size based on your child’s height and then size up for extra room.

If 0.8 isn’t a warm enough TOG rating, the sleep sack also comes in versions with a TOG of 1.2 or 1.5.

Helpful Amazon review: ”My 18 month old got too big for the sleep sacks but I’m not comfortable putting a blanket in the crib. This works perfectly, great weight and super soft. I love how this works over any pajamas and will be perfect during the months in the summer when we have the ac on or the winter”

• Available sizes: 12M-2T —3T-4T

7. A Sleep Sack & Swaddle Combo

• TOG rating: 1.5
• Recommended age: 0 to 6 months, depending on size

According to Dr. Segura, sleep sacks can be a helpful next step after your baby has outgrown their swaddle and started to roll. This adjustable design from HALO is a great option if you don’t want to buy separate swaddles and sleep sacks as your baby makes the transition. The three-stage design works as a traditional swaddle, keeping your little ones’ arms tucked against their body, but then it allows for one hand to be free for self-soothing. Finally, you can use it as a typical sleep sack with two arms out. It’s made from two layers of soft, breathable cotton muslin, and while the TOG score is 1.5, reviewers report that it feels lightweight enough for summer, though you may want to skip it on hot nights. The zipper closes from the bottom to the top and there’s plenty of room for babies’ legs to move and kick. With over 40 available prints and patterns, there are a lot of adorable options to choose from Plus, it’s machine washable.

Helpful Amazon review: ”My baby loves moving her arms freely, but also loves being swaddled. So this was a perfect match for us! And if it gets too cold, we can always swaddle her arms in to keep her warm, since it can be used both ways! It’s warm and soft, but light enough that she could still use it in summer. Highly recommend!”

• Available sizes: Preemie — Small

Expert:

Dr. Florencia Segura, MD, FAAP, board-certified pediatrician at Einstein Pediatrics