How to keep your baby safely warm, day and night
It’s three in the morning. Your baby is restless, the hands feel cold, and you’re wondering: add another layer, or not? You’re not alone — this is one of the most common questions I get from parents and maternity nurses.
In this article, I explain why babies cool down so quickly, how to reliably check if your little one is cold, and which products — and especially which combinations — keep your baby safely at the right temperature.
Why babies cool down so quickly
A newborn baby cannot yet regulate their body temperature well. Babies have a relatively large body surface, little fat reserve, and lose a lot of heat through their head. In neonatology, warmth is one of the first things we watch for: a baby who is cold uses energy that should be used for growing, feeding, and sleeping peacefully.
A baby with a good temperature is often visibly more relaxed: sleeping more calmly, feeding better, less restless.
How to check if your baby is cold
Cold hands and feet mean little — they are almost always a bit cooler in babies. Instead, feel with two fingers on the neck or between the shoulder blades:
- Does the neck feel comfortably warm and dry? Then you’re good.
- Does it feel cool? Then add a layer.
- Does it feel clammy or sweaty? Then your baby is too warm and you should remove a layer.
Other signs a baby is cold: restlessness or becoming unusually quiet, difficulty falling asleep, short sleep, and pale or mottled skin.
What temperature do you want to see — and what to do at each value?
Officially, 36.5 to 37.5 degrees is often called a 'normal' temperature for a baby. From my years in neonatology, I prefer to be more precise: aim for 36.7 to 37.2 degrees. Within this range, the temperature remains stable without large fluctuations — and that’s exactly what you want, because above 37.3 degrees, newborns often already show effects on their breathing. A baby with a stable temperature breathes more calmly, feeds better, and sleeps more deeply.
When in doubt, always measure the temperature properly (rectal is most reliable for a newborn) and use the neck check in between.
| Temperature | What it means | What to do |
|---|---|---|
| 36.7 – 37.2 °C | Just right | Do nothing — keep it that way. Check the neck in between instead of measuring again. |
| Below 36.7 °C | A bit too cool | Step 1: Put on a (woolen) hat and a bodysuit under the clothes. Measure again after 30 minutes. |
| Still below 36.7 °C | Need more warmth | Step 2: add an extra wool blanket, tuck in well. Measure again after 30 minutes. |
| If your baby remains cold | Skin-to-skin — the fastest way | First step: skin-to-skin. Your baby in only a diaper against your bare chest, hat on, and over that the unfolded Wrap Snuggle or a blanket over both of you. Offer a feeding: drinking helps warm up. Note: skin-to-skin only works with real skin contact; it’s ineffective if the baby is dressed. If skin-to-skin isn’t possible for a moment, dress your baby in all layers: bodysuit + hat + booties + snuggle + blanket. |
| Below 36.0 °C, or after the steps not above 36.5 °C | Too cold — seek help | Call your midwife, maternity nurse, or doctor, especially if your baby is also lethargic, drinking poorly, or looks pale. Meanwhile, keep your baby warm skin-to-skin (only a diaper, hat on) with the wrap or blanket over both of you. |
| 37.3 – 37.7 °C | On the warm side | Remove a layer, take off the hat indoors. Not near the heater or in the sun. Measure again after 30 minutes. |
| 38.0 °C or higher | Fever — seek help | Fever in a newborn is always a reason to immediately call your doctor or midwife. |
Why merinowool works so well here
Merinowool does something that cotton and synthetic fabrics cannot: it adapts to your baby's temperature. The fiber insulates when it’s cold and releases heat and moisture when it gets warm. This helps maintain that narrow, stable balance — without fluctuations to too cold or too warm.
All products that help with this are gathered in one collection: Everything to keep your baby warm.
Which products help — and when
For the night
- Sleeping bags — the safe foundation for every night: no loose fabric near the face, no kicking off.
- Sleepsuits — a sleepsuit that keeps the whole body warm, even if your baby crawls out of a blanket.
- Wool blankets — for over the sleeping bag on cold nights, or tucked into the cradle: under the armpits and securely fastened.
For daytime and the maternity period
- Baby cocoons & Snuggles — provide newborns with the boundary and warmth they know from the womb. Ideal for calm moments during the day, under supervision. The unfolded Wrap Snuggle is also perfect over skin-to-skin contact.
- Wraps — quickly add a layer during feeding or visits, without having to change your baby.
For on the go
- Beanies — babies lose up to a third of their heat through the head. Outdoors, a beanie is actually a good idea during the first months.
- Baby booties — keep feet warm without squeezing, also in the carrier or stroller.
- Wool liners — insulate from below in the stroller or car seat, where cold often creeps in unnoticed.
What do you put underneath? The combinations
The question I get most often. Think in thin layers of natural material — together they retain more warmth than one thick layer, and you can easily adjust.
Under a sleepsuit
- In a bedroom of 18–20 degrees: a short- or long-sleeve bodysuit is enough.
- Colder than 18 degrees: a long-sleeve bodysuit, optionally with a thin wool blanket over the mattress or the sleepsuit.
- Warmer than 20 degrees: just a thin bodysuit, or even just a diaper with the sleepsuit.
Under a snuggle or cocoon
- Indoors: a bodysuit or thin romper is enough — the cocoon does most of the work itself.
- Outside or in a cool house: a romper plus a beanie. The cocoon then replaces the jacket.
In a sleeping bag
- Summer: just a bodysuit.
- Winter: long-sleeve bodysuit and optionally a thin pajama or woolen pants.
And always: check the neck after fifteen minutes. Warm and dry means the combination is right — every baby is different, and that small gesture says more than any chart.
Too warm isn’t good either
Good to know: we want to prevent overheating just as much as cooling — above 37.3 degrees you can already see effects on newborns’ breathing. Don’t use thick synthetic layers on top of each other, keep the head uncovered indoors during sleep, and trust breathable, natural materials. That’s why at Moalie we work with merino wool: it regulates temperature in two directions.
All together
Want to see at a glance what keeps your baby warm? Then check out our collection Everything to Keep Your Baby Warm — curated from nearly 30 years of experience with newborns, for peaceful nights. For both of you.
Daniëlle Kempers is a neonatal nurse and baby coach, and founder of Moalie. Wondering if your baby is at the right temperature, or have a specific question? Feel free to contact us.