0–3 months
Merino Fitted Swaddle
Stop swaddling at the first signs of rolling, and do not use it past 3 months.
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Dress for the room, not the season.
Nursery temperatures shift overnight. Merino buffers the swing, but what goes underneath still matters. Use a room thermometer and this chart as your starting point.
Then trust the chest check: warm and dry is right; sweaty or hot means remove a layer.
What to wear, by room temperature
| Room temperature | Sleep sack | Underneath |
|---|---|---|
| Above 75°F / 24°C | Skip the sleep sack | A sleeveless merino singlet bodysuit on its own. |
| 72–75°F / 22–24°C | 3-Seasons Sleep Sack | Over a sleeveless merino singlet bodysuit. |
| 68–72°F / 20–22°C | 3-Seasons Sleep Sack | Over a long-sleeve merino bodysuit. |
| 61–68°F / 16–20°C | 3-Seasons Sleep Sack | Over a long-sleeve merino bodysuit and a merino onesie. |
| Below 61°F / 16°C | Quilted Winter Sleep Sack | Over a long-sleeve merino bodysuit. |
Check baby’s chest or the back of their neck: warm and dry is right; sweaty or hot means remove a layer.
The right layer at every stage
3–24 months
3-Seasons Sleep Sack
One size, made long. Fasten the underarm snap domes for a smaller baby.
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Colder rooms
Quilted Winter Sleep Sack
Extra warmth with merino wadding, for rooms below 61°F / 16°C.
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FAQ
Questions about sizing, layering or care? Our team replies within 1 to 2 business days.
Get in touchWhich sleep sack suits our room?
The 3-Seasons Merino Sleep Sack is our lighter option, designed for milder rooms across spring, summer, and fall. For colder rooms, our Quilted Winter Sleep Sack provides extra warmth with merino wadding.
When can a newborn start wearing the sleep sack?
Our sleep sacks fit from 3 to 24 months (37½ inches long). For babies under 3 months, use our Merino Fitted Swaddle. Transition out of the swaddle to the sack at the first signs of rolling.
How do I know if the one-size sleep sack fits safely?
Always check that the neck and arm openings sit comfortably snug so baby cannot slide down inside the sack. Discontinue use if openings are too loose or fit is too tight.
Will wool make my baby too hot or sweaty?
Merino takes up sweat as vapor and releases it before skin turns clammy, but dressing for the room is still key. Check baby’s chest or the back of their neck: warm and dry is right; sweaty or hot means remove a layer.
Is the Merino Cable Knit Blanket suitable for baby sleep?
Our blanket is designed for daytime stroller walks, couch cuddles, and tummy time, or a toddler bed later. Under safe sleep guidelines, keep cribs free of loose blankets for infants under 12 months.