A sleep sack works best as part of a simple, safe sleep space. Start with a firm, flat crib mattress and a fitted sheet from our organic crib bedding. Under the sleep sack, dress your baby in a breathable organic bodysuit or footie, depending on the room temperature and TOG rating.
Save baby blankets for swaddling and supervised awake time. Our safe sleep setup checklist and sleep transition gear checklist walk you through each stage, and the DreamLog sleep tracker helps you follow your baby's sleep patterns.
Frequently Asked Questions
What is a sleep sack?
A sleep sack, also called a wearable blanket or sleep bag, is a sleeveless garment that zips or snaps over your baby's clothes. It keeps them warm through the night without loose blankets in the crib, and most have a zip that opens from the bottom for easy diaper changes.
Are sleep sacks safe for babies?
Yes. The American Academy of Pediatrics recommends wearable blankets over loose blankets for infant sleep. Choose one that fits well at the neck and armholes so your baby can't slip down inside, and avoid weighted sleep sacks, which the AAP advises against.
What does TOG mean?
TOG (thermal overall grade) measures how warm a sleep sack is. As a general guide, a lower TOG around 0.5–1.0 suits warm rooms, a mid TOG around 1.0–2.0 suits moderate temperatures, and a higher TOG around 2.5 suits cooler rooms. Check each brand's temperature chart for exact recommendations.
What should my baby wear under a sleep sack?
It depends on the room temperature and the sleep sack's TOG rating. In a warm room, a short-sleeve bodysuit under a light sack may be enough. In a cooler room, try a long-sleeve bodysuit or footie. Feel your baby's chest or back of the neck: it should be warm, not hot or sweaty.
What's the difference between a swaddle sack and a sleep sack?
A swaddle sack holds your baby's arms snugly for the newborn weeks. Once your baby shows signs of trying to roll, you need to stop swaddling with arms in. A transitional swaddle sack or regular sleep sack with the arms free is the next step.
What is a baby sleep gown?
A sleep gown is a soft newborn garment with an open or elasticated bottom hem instead of snaps, which makes middle-of-the-night diaper changes much faster. If your gown set comes with a matching hat, remove the hat before placing your baby down to sleep, to prevent overheating.
What size sleep sack should I buy?
Choose by your baby's weight and length using the brand's size guide, not just their age. A sleep sack should be roomy enough at the hips for the legs to move freely, but snug at the neck and armholes. Avoid sizing up too far, because a sack that's too big can ride up over the face.
Do you offer free shipping and returns on sleep sacks?
Yes. Every order ships free with hassle-free returns, and first-time customers get 10% off at checkout, up to a maximum discount of $75. See our shipping and returns pages for details.
