Merino Wool for Baby Sleep: Benefits, Safety and What Parents Should Know
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In light of the May 2026 BBC exposé on unsafe sleep advice, many parents are understandably questioning who to trust when it comes to their baby’s sleep.
As someone who speaks with parents regularly and sells baby sleepwear, I want to be clear about my role, while also sharing evidence-based information about merino wool and baby sleep.
My background (and an important disclaimer)
I have a Consumer & Applied Science Degree from The University of Otago in Clothing and Textile Science which means I learnt the basic science of fibres, yarns and fabrics and how they interact with the human body. This includes thermoregulation which relates to overheating, a significant risk factor in sudden infant death syndrome. I am also a mum who grew up in New Zealand where merino wool is widely used for babies, and I have completed a short course with The Lullaby Trust on how to speak about safe sleep.
I am not a medical professional or sleep consultant and I've never claimed to be! Just to be totally clear.
My aim is to support parents with fibre and fabric knowledge to make informed decisions, to make merino wool a more widely-known option in the UK, while always encouraging parents to follow official safe sleep guidance.
Trusted safe sleep guidance for babies
The trusted authorities I often refer to include:
Plunket states: "We recommend putting babies and young children to sleep in natural, breathable fibres like cotton and wool. To help keep them warm use layers, adding and removing them as needed to help them maintain a comfortable body temperature. Light merino wool blankets and wraps are perfect choices as they are breathable and help little ones maintain their body temperature." (May, 2026)
Why merino wool is used for baby sleep
Merino wool is a natural fibre known to support comfort during sleep for all ages.
The scientifically proven, key benefits of merino wool for babies (and how it differs from other fibres):
- Breathable: allows heat to escape (synthetic fibres like fleece trap heat)
- Thermoregulating: helps maintain a stable body temperature (merinos secret sauce)
- Moisture-wicking: absorbs moisture without feeling damp (where cotton can fail)
- Soft on skin: suitable for wearing directly against baby’s skin (where wool from the merino breed of sheep surpasses other sheep wool)
These properties are why merino is commonly used in baby sleepwear in countries where the merino breed of sheep thrive so it's been used for decades, like New Zealand and Australia.
Is merino wool safe in warm temperatures?
This is an area where clarity really matters. Scientific evidence includes:
- Merino wool performs well across a range of temperatures
- Its breathability may help reduce the risk of overheating compared to synthetic fabrics
- It can be worn directly against baby’s skin, provided it is high-quality, superfine merino (like we have at yes merino)
But, let's be clear: No fabric replaces the need to monitor your baby, especially in warmer conditions.
Has the guidance changed?
Guidance should change over time as science and data give the experts more clarity alongside lifestyles changing. The resources, information and options we have today are very different to only a few years ago.
Very recently, "natural, breathable fibres" were recommended for safe sleep by all the authorities I could find globally, and in many places it still is. In the UK, the focus now appears to be more on the room temperature and the sleep space than sleepwear.
My opinion is that this guidance has had to adapt to big changes in the nursery and babywear market which has exploded with every type of sleep space, gadget and cute toy imagineable, of which many can create suffocation risks. We can also measure and manage the room temperature much more easily and affordably than we could only a decade ago so it makes sense to encourage parents to do so.
The focus in the UK for sleepwear and bedding has moved to using sleeping bags and lightweight layers (May, 2026). I cover my opinion on this is in a more detailed blog here but ultimately, merino wool sleeping bags and lightweight blankets still meet this criteria with shining colours!
What does the research say?
Some studies (including research associated with the University of Sydney) suggest that wool may:
- Support longer and deeper sleep
- Improve sleep efficiency
- Help maintain a more stable sleep temperature
There is also evidence linking wool sleep environments with improved comfort in infants. However, it’s important to be balanced, these studies are supportive, not definitive, and should not be treated as medical claims.
How I guide parents
When parents contact me, I always come back to the same principles:
- Every baby is different
- Room temperature matters
- Check your baby regularly
- Adjust layers as needed
- Be especially mindful in warm weather
For example, over a recent Bank Holiday, a parent asked whether her newborn could wear one of our merino pieces in a warm room and if so, should they have a cotton vest underneath.
I explained that merino can support thermoregulation in warmer temperatures and is safe against the skin but also emphasised the importance of ongoing monitoring and adjusting based on her baby’s needs. I will always start with the fact that every baby is different though! There's never one simple answer which can be difficult to hear but we aren't all living in test environments, even if we did have exactly the same babies!
Final thoughts: where merino fits in safe sleep
Merino wool is an option for baby sleep because of its breathability and temperature-regulating properties. I personally think it's often the best option! But it is never a safety solution on its own.
Safe sleep is built on:
- Following trusted, up-to-date guidance
- Keeping baby at a safe temperature
- Staying attentive to your baby’s cues
No fabric replaces informed, responsive caregiving but it's really helpful to understand the basics and the options you have.
I found the best option for my baby to sleep in almost year-round to be merino wool sleeping bags because they have a reduced suffocation risk and reduced overheating risk. I knew the merino was working with my sons body naturally to cool him down on warmer evenings then warm him when the cooler mornings came around.
We also used a lightweight merino wool blanket daily and a heavier weight merino wool blanket, particularly for travel when we weren't sure what the room temperature would be or whether we would be able to manage it.
These merino wool beauties also didn't need washing as often (which is always a win!)