Winter baby sleep guide: How to keep your baby cosy and safe all season long

Baby boy sleeping at night

by Anne Lora Scagliusi |
Updated on

Winter has its cosy benefits—snuggly evenings, chilly walks, and maybe even some snow! But as temperatures dip, many parents worry about keeping their babies both warm and safe through the night. While cooler temperatures can actually support better sleep by aiding the body’s natural cooling process in the evening, winter can also bring unique challenges, especially for safe baby sleep.

Here’s everything you need to know for peaceful winter nights, with expert advice from the pros on keeping your baby comfortable without overheating.

Keep an eye on baby’s temperature

Babies rely on us to stay cosy because they don’t regulate their body temperature as well as older kids and adults. In fact, babies can lose heat rapidly, as much asfour times more quickly than adults. Also, babies under six months can’t shiver to warm themselves, and young babies don’t have much body fat to help retain warmth.

Check their chest: Jenny Ward, CEO of The Lullaby Trust, advises “You need to check your baby to make sure that he’s a comfortable temperature when he goes to bed. Put him down in his cot and slip your hand under his bed clothes to touch the skin of his chest. If he feels cold, try adding one more layer—a vest under his sleepsuit, or one light blanket.”

Signs of overheating: Jenny also warns, “The clearest sign that your baby is too warm is his skin feeling clammy. Other signs would be a baby who is sweaty or flushed or has damp hair. If he’s too hot, take one—or more—layers away.” Keep in mind that newborns may not be able to sweat to cool down, as sweat glands take a few weeks to develop fully.

Set up the room just right

Your baby’s room temperature is a big factor in maintaining the right level of warmth.

Ideal room temperature: The NHS recommends that babies under four weeks old sleep in a room around 18°C, and between 16-19°C for babies over four weeks. Jenny explains, “The advice is that all babies should sleep in the same room as you when they’re under six months old. When you’re physically present with them, you’ll be aware of whether the temperature is comfortable for sleep.”

Be cautious of hot spots: Avoid placing your baby’s crib too close to a radiator or heater, as this can make them overheat or even burn their skin. “Make sure your baby’s cot isn’t right next to a radiator,” says Jenny, “and make sure the cot isn’t positioned in a spot where it will be in direct sunlight during the day. Even winter sunshine can be hot enough to make youngsters overheat.”

Keep the cot simple and safe

It can be tempting to add cosy items to a baby’s cot during winter, but less is more when it comes to safe sleep.

Clear the cot: “The safety rule for cots is to keep them clear. The safest mattressis one that’s firm, flat, and waterproof. You need a flat sheet, firmly tucked in, under your baby. Natural fabrics, like cotton or bamboo, are soft and breathable, so they help to regulate your baby’s temperature,”Jenny explains.

Avoid extra items: Babies under 12 months shouldn’t have pillows or duvets in their cot. Jenny cautions, “A pillow is soft, so your baby’s head sinks down into it, creating a little pocket of warm air around his head. He’s too small to move out of that position—so he could get dangerously hot.”

Skip the hot water bottle: “There are also concerns with adding anything that isn’t totally flat into your baby’s cot,” Jenny adds. “So, we advise against additional items like pods or cot bumpers. And never have a hot water bottle in bed with your baby. It could easily make him too hot. Keep the cot clear!”

Choose the right sleepwear and layers

Sleepwear choices can vary depending on your baby’s comfort, the room’s temperature, and your home’s unique environment. Here’s how to get it right:

Focus on layers: Sarah Patel, founder of Teach To Sleep and baby and toddler sleep consultant, says, “If you think your baby is cold, add an extra blanket or layer of clothing to your baby. Avoid thick, padded blankets or duvets if they’re under 12 months, as these increase the risk of overheating.”

Follow sleep bag guidelines: Some sleepwear brands offer guidelines based on room temperature. Jenny recommends, “The most important thing is to check your baby to make sure that he’s a comfortable temperature when he goes to bed.”

Feet-to-foot position: Sarah recommends, “Always place your baby’s feet at the foot of the crib. This position can prevent blankets from covering their head while they sleep.”

Practical tips for bed-sharing in winter

If you’re bed-sharing with your baby, Sarah says to keep these pieces of advice in mind.

Use a sleeping bag: The Lullaby Trust recommends that, when bed-sharing, you use a baby sleeping bag rather than loose blankets, which can pose risks.

Adjust your bedding: Keep your bedding at waist height to avoid it accidentally covering the baby. Sarah says, “The warmth generated by an adult in the same bed as a baby may create a warmer environment, so adjust bedding and/or clothing for your baby accordingly.”

Sleep expert baby winter sleep safety do’s and don’ts

Rosey Davidson, infant sleep consultant and founder of Just Chill Baby Sleep, shares her top “Do’s and Don’ts” for baby winter sleep safety.

Dos

  • Dress your baby in a well-fitted sleeping bag or baby-safe layers based on the room temperature (and their personal presence. Each baby is slightly different). Use layers that can be added or removed as needed.

  • Check their chest or back – these areas should feel warm, not hot or cold. Avoid gauging by hands and feet, as these can often feel cooler. If the chest or back feels cool, consider adding a layer.

Don’ts

  • Avoid hats, loose blankets, or excess bedding in the crib, as these can increase the risk of overheating and SIDS (remember no pillows for under 12 months too.)

  • Over-bundling or using heavy blankets.

  • Heating the room too much – a room temperature of 16-20°C is ideal. We actually sleep better in a cooler room with warmer bedding; than a hot room with less bedding.

Safe sleeping in winter baby FAQs

What TOG sleeping bag should I use for winter?

A 2.5 TOG sleeping bag is recommended for winter, but always refer to the specific guidelines of your sleep bag brand. The 3.5 tog is perfect for temps below 18 degrees in baby's room.

How should I dress my baby for sleep in winter?

Use layers like a bodysuit with a sleep bag, adjusting based on room temperature and comfort.

Should my baby wear a hat while sleeping in winter?

No, as hats can trap heat and increase the risk of overheating and SIDS. The baby’s head should always be uncovered.

Winter baby safety sleep products we love

The GroEgg2 Room Thermometer and Nightlight by Tommee Tippee is a digital thermometer designed to make temperature monitoring easy and visual. Its large, bright display changes colour based on the room's temperature, helping parents quickly determine if the room is at a safe temperature for their baby. It also functions as a nightlight, with three adjustable brightness levels for a calming ambiance.

Review: "It’s very quick and easy to look into your child’s room and see if it is at the target temperature. Has made it easier to know how many layers to dress her in to ensure that she won’t overheat and isn’t too cold. I can even see the glow on the baby monitor. No set up required, just plug in and go. Great product."

Read our full Tommee Tippee GroEgg2 Room Thermometer and Nightlight review

Pros

  • Colour-coded temperature display for easy visual checks
  • Acts as a nightlight with adjustable brightness levels
  • Modern design that fits easily into any nursery.

Cons

  • Requires a power source, so it must stay plugged in

This ergoPouch Sleep Onesie in Hedgehog is a cosy winter onesie for toddlers and children, offering a 2.5 TOG rating ideal for temperatures between 17-23°C (63-73°F). Made from soft organic cotton, this onesie keeps kids warm while allowing freedom of movement, and its 3-way zip makes nighttime changes convenient. Foot cuffs provide additional warmth to toes, making it perfect for active sleepers.

Pros

  • Made from organic cotton, gentle on sensitive skin
  • 3-way zip for quick and easy nappy changes
  • Provides freedom of movement, ideal for kids transitioning to big beds

Cons

  • Designed for specific temperature ranges; may require layering for colder rooms

This 3.5 TOG baby sleeping bag featuring Peter Rabbit is designed to keep babies warm without the need for blankets, making it a good choice for colder months. The thick, padded design provides extra warmth, and the detachable sleeves offer versatility as temperatures vary, adapting the sleeping bag to milder conditions.

Review: "Really warm and super comfy.Removable sleeves so baby doesn’t get too hot. Perfect fit."

Pros

  • High TOG rating (3.5) for extra warmth, ideal for winter
  • Detachable sleeves allow for temperature flexibility
  • Prevents blanket kick-off, keeping babies consistently warm

Cons

  • Limited to very cold environments, so may be too warm for rooms with high temperatures

This White Cable Knit Sherpa Fleece Blanket from JoJo Maman Bébé is the perfect winter essential. Its cosy design makes it versatile enough to use as a blanket on beds or keeping little ones toasty during chilly walks in the pram. Made from soft cotton with a plush sherpa polyester lining, it provides warmth and comfort. 

The NHS advises blankets should be tucked in firmly, no higher than the shoulders, and not doubled over as this can cause overheating.

Pros

  • Made from soft cotton, gentle on sensitive skin
  • Sherpa fleece backing provides added warmth
  • Versatile and can be used in various settings (prams, beds, etc.)

Price: £219

A favourite among parents, this mattress combines Coconut Coir, Natural Latex, Wool, and Cotton for 100% natural comfort, free from harmful chemicals. The wool provides natural insulation to keep your baby warm during winter, while the breathable coconut coir promotes airflow, ensuring a cosy and safe sleeping environment from infancy to toddlerhood.

Review: “Knowing that the mattress is hand-made from four natural breathable materials with no harmful chemicals or toxins gives me peace of mind. The materials are also temperature regulating, which ensures the baby does not get too hot,” she said. Chris agreed, "We would say that our daughter was also able to regulate her temperature effectively during testing – at no point was there any evidence of her getting too hot while sleeping on the mattress."

Read our full The Little Green Sheep Group Twist Natural Cot Bed Mattress review.

About the experts

Jenny Ward is CEO of The Lullaby Trust, which raises awareness of sudden infant death syndrome (SIDS) and provides expert advice on safer sleep for babies; lullabytrust.org.uk,and a mum of two.

Sarah Patelis a dedicated mom of two young children, just 18 months apart, and a Certified Baby and Toddler Sleep Consultant. As the founder of Teach To Sleep, she brings over 15 years of experience as a primary school teacher and senior lecturer in education to her practice.

Rosey Davidson is founder and CEO of Just Chill Baby sleep, an infant sleep consultancy focused on providing straight forward, no-nonsense sleep advice to parents. As a successful businesswoman and content creator with a large social media following (@just_chill_mama).

About the author

Anne Lora Scagliusi is a Senior Digital Writer at Mother & Baby. She is a Scotland-based journalist with over a decade of international writing experience, specialising in women’s health, maternal mental health, and wellness. Her work has been featured in Vanity Fair, Marie Claire, and Glamour and has appeared on several Vogue global editions. She is mum to a one-year-old bambino and lives between Italy and the UK. You can follow her on Instagram.

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Mother & Baby is dedicated to ensuring our information is always valuable and trustworthy, which is why we only use reputable resources such as the NHS, reviewed medical papers, or the advice of a credible doctor, GP, midwife, psychotherapist, gynaecologist or other medical professionals. Where possible, our articles are medically reviewed or contain expert advice. Our writers are all kept up to date on the latest safety advice for all the products we recommend and follow strict reporting guidelines to ensure our content comes from credible sources. Remember to always consult a medical professional if you have any worries. Our articles are not intended to replace professional advice from your GP or midwife.