Sweltering nights and sweaty blankets are no fun for little babies. They're not as good at regulating their own body temperature as we grown-ups are and, of course, while we can get up, strip off and reposition a fan to cool down, that's not part of their skill set yet.


But it's not just about being uncomfortable: overheating can be properly dangerous for babies. That's because getting too hot can increase their risk of SIDS (sudden infant death syndrome).

There are some simple things you can do to make sure your baby doesn't overheat, though. And it all comes down to knowing what temperature is best for your baby's room and how many layers your baby needs when sleeping...

What's the best temperature for my baby's room?

A room temperature of between 16ºC to 20ºC (60.8°F to 68ºF) is recommended. In fact, 18ºC (65ºF) is just right, say safe-sleep experts at the Lullaby Trust.

It's not easy to tell just by guessing how hot or cold a room is but there are some really good, and not too pricey, room thermometers out there which are well be worth investing in.

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When it's really hot outside, it's hard to keep your baby's room at the ideal temperature, even if you open doors and windows (safely, of course) or maybe use a fan (not aimed directly on your baby). In these circumstances, you'll need to lighten the layers of clothing your baby is wearing while they sleep, as well as lightening or reducing their bedding.

How many layers does my baby need when sleeping in hot weather?

If you normally use sheets and blankets and put your baby in a sleepsuit at bedtime, use our video guide (at the top of this article) to see how many layers they'll need, according to the temperature in your baby's room (please do remember that, as safe-sleep experts advise, all sheets and blankets should be firmly tucked in and not above shoulder height).

You can also check our chart below:

chart showing how many sheets and blankets a baby needs at various temperatures of hot weather

What if my baby sleeps in a baby sleeping bag?

If you prefer to put your baby in a sleeping bag and ditch the sheet and blankets, see our sleeping bag hot-weather video guide, above, to see what you dress your baby in underneath the sleeping bag and/or which Tog sleeping bag is best, according to the temperature in your baby's room.

You can also check our chart below:

chart for layers for baby sleeping in hot weather

What if I don't have a room thermometer?

"If you're feeling hot, then your baby will be, too," says MadeForMums expert and NHS community midwife Anne Richley. "As a guide, think about what you'd be comfortable sleeping in, and add 1 extra layer for your baby.

"So, if you don't need any covers, your baby probably only needs 1. If you’re sleeping naked, then a sleepsuit and no blankets for your baby will be just fine. In very hot conditions, your baby may not even need the sleepsuit and can sleep in just their nappy.

Why do some babies get so sweaty – and is it safe?

Sweating is natural – it's a way for our bodies to cool us down. (The dampness on our skin actually helps us to pick up the coolness from any moving air). But you'll find some babies sweat more than others. If your baby feels very sweaty, check to see how hot they are by feeling the back of their neck.

"If your baby’s hot to the touch," says Chireal Shallow, psychologist, sleep expert and author of The Gentle Sleep Solution, "wipe them down with a damp towel – on the face, neck, arms and legs – and open internal doors and windows, so a natural, flowing breeze is created."

It's also a good idea to try to keep your home cool throughout the day. In the UK, we tend to fling open curtains and windows the moment there's sunshine but, in Mediterranean countries, people keep the heat out with unopened curtains. This avoids a greenhouse effect, where the heat builds up and up inside.

Don't panic if your baby is sleeping more soundly than usual when it's hot. "The heat can make us all lethargic, which is quite natural," says Chireal. "I wouldn’t get too worried unless you have problems rousing your baby or they display odd behaviour."

baby sleeping on their back in empty cot

Will overheating harm my baby?

We've mentioned above that there are well-established concerns that overheating can increase the risk of Sudden Infant Death Syndrome (SIDS). But that doesn't mean you should get overly anxious during hot spells: research suggests that babies are actually more likely to overheat when they're overdressed in cold weather.

"Although heat stress is undoubtedly a contributing factor in some unexpected infant deaths, heat stress seems, paradoxically, to be more of a problem in cold weather when parents may wrap their baby more heavily," says Peter Fleming, Professor of Infant Health at the University of Bristol.

"With excess wrapping, your baby may find it hard to cool down and can become heat-stressed. Babies don't really need much more wrapping up or clothing than adults in hot conditions. It's unlikely a little one would come to harm from high ambient environmental temperatures that an adult could cope with.

Most importantly, you should ensure that there's no possibility of your baby's head becoming covered with bedding or clothing. Babies can lose heat really effectively, when necessary, from their head.
Professor Peter Fleming, University of Bristol

And, of course, you should be sure always to put your baby down to sleep on their back. "One of the possible reasons why putting babies to sleep on the front leads to an increased risk of unexpected death," explains Professor Fleming, "is that it is harder to lose heat when you're sleeping on the front.

"When the weather is very hot, people will be much more likely to sleep on their backs as they can keep cool more easily in this position.

"This is not the only reason that babies should never be put to sleep on the front – sleeping on their front is a major risk for babies regardless of the environmental temperature – but it may be helpful for parents to understand how to ensure their baby is neither too hot nor too cold."

About our experts Anne Richley, Chireal Shallow and Professor Peter Fleming

  • Anne Richley is a midwife with 22 years' experience. She is currently Matron for Community Midwifery Service at Northampton General Hospital NHS Trust. has written a number of books on pregnancy and babies, including Your Baby's First Year.
  • Chireal Shallow is a sleep expert. She is an HCPC registered psychologist and BABCP accredited psychotherapist with over 20 years experience of working within both the NHS and private settings. She is Director for the Association of Sleep Consultants. She appears regularly on TV and is also a mother of 4.
  • Peter Fleming is Professor of Infant Health & Developmental Physiology at the University of Bristol Medical School. He is a neonatologist, paediatrician, epidemiologist and developmental physiologist, with an expertise in the investigation and prevention of causes of death and disability in children.

Video production: Janet Mtima and Emily Longman-Wall
Illustrations: Jordan Edmonds-Moore
Pic: Getty


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