Quick answer
For cold-weather sleep, dress your baby in a base layer, add a sleep sack or blanket only if the room is below 68°F, and use a thin hat only for the first 10–15 minutes of sleep or during a feed. Remove the hat once your baby is asleep to prevent overheating. Always place blankets below the armpits and never cover the face.
Check the room temperature before you add layers
Set the nursery between 68–72°F (20–22°C) for safe sleep. If the room is in that range, a cotton onesie and a 2.5 tog sleep sack are usually enough. Only add a hat or blanket when the room drops below 68°F, and never use both a hat and a heavy blanket at the same time for a sleeping baby. A simple thermometer near the crib helps you decide without guessing.
Choose breathable organic layers over thick synthetics
Organic cotton breathes and wicks moisture, so it helps regulate temperature better than polyester fleece. For the base layer, use a snug-fitting organic cotton onesie or pajama. If you use a blanket, pick a lightweight organic cotton one like the Everything Organic Baby Blanket, which is 40" x 40" and made from 100% organic cotton. For colder nights, a sleeveless winter sleep sac with three layers of organic cotton adds warmth without trapping heat around the head and neck.
Use a hat only for short periods and never for unsupervised sleep
A baby hat for sleep can help during a night feed or when you first put your baby down in a cool room, but it should come off once they are asleep. Babies lose most of their heat through their head, and a hat that stays on all night can cause overheating. If you use a hat, choose a thin, snug organic cotton one with no ties or pom-poms. Check your baby's neck and chest—if they feel hot or sweaty, remove the hat immediately.
Place blankets below the armpits and tuck them securely
If you use a blanket for a baby under 12 months, place it over the lower half of the body, no higher than the armpits, and tuck the edges under the mattress on both sides. This keeps the blanket from riding up over the face. The Everything Organic Baby Blanket is lightweight enough to tuck without bulk, and its 40" x 40" size works well for this. Never use a loose blanket in a crib with a baby who can roll or scoot.
Adjust layers as the night goes on
Body temperature drops in the early morning, so a layer that felt right at 8 p.m. may be too warm by 2 a.m. If you use a sleep sack, you can unzip the bottom for a quick diaper change without removing the whole sack. For a blanket, check your baby's chest and back of the neck—if they are damp with sweat, remove one layer. A good rule: if you are comfortable in a t-shirt, your baby likely needs one more layer than you.
Step-by-step layering for cold-weather sleep
- Start with a snug organic cotton base layer: Dress your baby in a fitted organic cotton onesie or pajama. Avoid loose fabric that can bunch up. Checkpoint: the fabric should lie flat against the skin without gaps. Common mistake: using a fleece or synthetic base layer, which can trap moisture and cause overheating.
- Add a sleep sack or tucked blanket if the room is below 68°F: Choose a sleeveless sleep sack like the Organic Winter Sleep Sac - Essentials for extra warmth, or tuck a lightweight organic blanket no higher than the armpits. Checkpoint: you should be able to slide two fingers between the sack and your baby's chest. Common mistake: using both a sleep sack and a blanket at the same time, which can cause overheating.
- Use a hat only for feeds or the first few minutes of sleep: If the room is very cold, put a thin organic cotton hat on your baby during a feed or while they fall asleep. Remove it once they are asleep. Checkpoint: feel the back of your baby's neck—if it's sweaty, remove the hat and one other layer. Common mistake: leaving a hat on all night, which can lead to overheating and is a risk factor for SIDS.
- Recheck layers after 2–3 hours and in the early morning: Body temperature drops overnight. Feel your baby's chest and neck. If they feel cool, add a layer; if damp, remove one. Checkpoint: keep a thermometer in the room and adjust based on the temperature, not the clock. Common mistake: assuming the layers you set at bedtime will still be right at 3 a.m.
Product facts that help with layering
- Everything Organic Baby Blanket: Made from 100% organic cotton, 40" x 40", with a playful print on one side and a coordinating solid on the other. Lightweight and easy to toss in your bag or the stroller. The lightweight organic cotton breathes well, so it can be used as a lower-body layer in a crib without adding excessive heat. The 40" x 40" size is large enough to tuck under a mattress on both sides for a baby under 12 months.
- Organic Winter Sleep Sac - Essentials: Three layers of pure, chemical-free 100% certified organic cotton, sleeveless design, and a chunky two-way zipper down the front. Use a onesie, romper, or gown underneath depending on temperature. The sleeveless design prevents overheating around the head and neck, making it a safer alternative to a hat for all-night warmth. The two-way zipper makes diaper changes easier without fully undressing your baby in a cold room.
