Cooler Nights: How to Pick a Fall Sleep Sack for Your Little One

The first properly cold nights of the year have a way of sneaking up on you. One week the window is cracked open; the next you're standing over the crib at midnight wondering whether your toddler is warm enough. For babies and young toddlers, a loose blanket isn't the answer — a wearable sleep sack is. Here's how to pick one for fall, and how to make the cooler weeks ahead easier on everyone.

Start with the weight, not the season

Sleep sacks are rated in TOG, a measure of how much warmth the fabric holds. A lower number means a lighter sack. Our Toddler Sleeping Sack with Feet is a 0.5 TOG, which makes it a practical year-round pick: light enough that it isn't too much on a mild night, and easy to build on when things get colder.

That last part is what most of us overlook. Rather than buying a different sack for every month, change what goes underneath it — short sleeves on a mild night, long-sleeve cotton pajamas once the thermostat drops, footed pajamas for the coldest stretch. One sack, three levels of warmth.

If you'd rather the sack itself do more of the work, the High End Comfort Cotton Baby Sleeping Bag is a sleeveless plush style made for spring, autumn and winter, cut loose so there's still plenty of room to kick.

The details you'll appreciate at 2 a.m.

• Which way the zipper runs. Both of these unzip from the bottom, so a diaper change doesn't mean unwrapping your child completely.
• Zipper protection. A cover at the top and along the teeth keeps the hardware off your baby's chin and belly. Small detail, noticeable difference.
• Room to move. A good sack is roomy enough for kicking but shaped so it can't be kicked off. Both of these run generous for exactly that reason.
• Foot openings. If your toddler is already walking, the footed version lets them walk to the crib on their own two feet instead of being carried in.
• Washability. The toddler sack is machine washable, and two in rotation means one is always clean and dry.

Useful well beyond the crib

A sleep sack earns its keep outside the nursery too. The cotton sleeping bag is made for the crib, the stroller, travel, picnics and camping, which is handy this time of year — a nap in a cool car or a chilly guest room goes better when your little one is wearing something familiar. That alone makes it worth packing for a weekend away.

One last suggestion: put the sack on as part of the bedtime routine instead of at the very last second. Zipping it up turns into a cue that the day is over, and on a dark October evening that's worth nearly as much as the warmth.

Cool nights are only getting started. Browse the rest of our kids and home essentials to get your evenings set up for the season.