Baby Sleep in the Heat: How to Keep Your Little One Cool and Safe

Baby sleep heat challenges are real — and with an unusually hot Bank Holiday weekend arriving in May, many parents across the UK are struggling. First, know that you are not alone

Warm nights genuinely affect babies, and the good news is that a few simple steps can make a big difference.

Below, our experts at Millpond Sleep Clinic share everything you need to know.

Why Temperature Affects Baby Sleep in the Heat

The ideal sleeping temperature for a baby is between 16°C and 20°C. So, when the mercury climbs above this — as it can easily do during a May heatwave — sleep quality drops quickly. Babies cannot regulate their body temperature as efficiently as adults. As a result, they wake more often, settle less easily, and become overtired.

Crucially, overheating is also a known risk factor for Sudden Infant Death Syndrome (SIDS). That is why our safer sleep advice always includes guidance on room temperature. In short, keeping your baby cool is about safety, not just comfort.

How to Cool Your Baby’s Room Before Bedtime

First, focus on the room itself. Even small changes to the environment can bring the temperature down by several degrees.

Close curtains and blinds early

Start this first thing in the morning. Blackout curtains or blinds are particularly effective because they block solar heat from building up throughout the day. As a result, the room stays several degrees cooler by bedtime.

Keep windows closed during the day

This surprises many parents, but it works. If the outside temperature is higher than inside — which is common during a UK heatwave — open windows to let hot air in. Instead, keep them shut until the evening, then open them once the outside air cools down.

Use a fan wisely

A fan is helpful, but position it carefully. Place it near an open window to draw cooler night air into the room. Importantly, never point it directly at your baby. Also, run it for 20–30 minutes before the bedtime routine begins so the room is already cooling when your baby goes down.

Use a room thermometer

Because 16–20°C can feel cooler than expected, a room thermometer removes the guesswork entirely. Check it before each sleep and adjust clothing and bedding accordingly.

Millpond tip: Pre-cool the room as early as 6 pm. Close the door to hold the cool air in, then begin your bedtime routine in a separate room.

Tips for Baby Sleep in the Heat at Night

Once the room is as cool as possible, turn your attention to your baby directly. Here are the most effective ways to keep them comfortable throughout the night:

Give a lukewarm bath before bed. Avoid cold water, as this can cause the body to retain heat. Instead, aim for a temperature that feels gently cool on your wrist.
Dress your baby in one light layer of cotton sleepwear — or simply a nappy on very hot nights. Natural fibres breathe far better than synthetic ones.
Switch to a 5 tog summer sleeping bag. This is lightweight enough for warm nights but still provides a familiar, safe sleep environment.
Check the temperature by feeling your baby’s chest or back, not their hands or feet. Hands and feet are naturally cooler and will mislead you.
Remove layers if your baby feels hot or sweaty. Never add extra layers “in case it gets cold later” — overheating is a greater risk than being slightly cool.

For more guidance on safe sleep, see our sleep advice videos.

Keeping Your Baby Hydrated in Hot Weather

Hydration is an important part of supporting your baby’s sleep in the heat. Babies dehydrate faster than adults, so feeds become even more important in warm weather.

Breastfed babies: offer feeds more frequently. Your breast milk will naturally adjust to provide more thirst-quenching foremilk. No extra water is needed before six months.
Formula-fed babies: alongside regular milk feeds, you can offer small amounts of cooled, boiled water from around six months.
Expect more night waking: your baby may wake more often simply because they are thirsty. This is completely normal in hot weather and should settle once temperatures drop.

Bank Holiday Weekend: Protecting Sleep When Routine Is Disrupted

A Bank Holiday heatwave brings extra challenges. For example, days out, later bedtimes, and more stimulation can all affect how well your baby sleeps. Here is how to manage:

Try to keep nap times as consistent as possible, even if the timing shifts by 20–30 minutes.
Consider an earlier bedtime if your baby has had a busy or hot day. Overtiredness makes it much harder for babies to settle, especially in the heat.
If you are staying away from home, bring your baby’s usual sleep cues: their sleeping bag, a comforter, and a small fan. Familiarity helps enormously in an unfamiliar room.
Finally, do not worry if sleep is not perfect over the weekend. Return to your normal routine on Tuesday, and most babies will resettle within a night or two.

Signs Your Baby May Be Too Hot

It is important to know what to look for. According to the Lullaby Trust safer sleep guidance, signs of overheating include:

Flushed or red skin
Rapid or noisy breathing
Unusual restlessness or crying
Feeling hot and sweaty on the chest or back

If you notice these signs, remove a layer immediately and offer a feed. If you are concerned, contact your GP or call NHS 111. You can also read the NHS advice on babies and hot weather for further guidance.

In Summary: Baby Sleep in the Heat

To sum up, helping your baby sleep in the heat takes preparation, but it is absolutely manageable. So, start by cooling the room early, dressing your baby lightly, using a room thermometer, and offering extra feeds. Give yourself grace over the Bank Holiday weekend — a few disrupted nights will not undo good sleep habits.

However, if sleep difficulties continue beyond the heatwave, we are here to help. Millpond Sleep Clinic has been supporting families with gentle, evidence-based sleep packages for over 30 years. Get in touch to find out how we can support you.

By Mandy Gurney RGN, RM, DipHV — Updated May 2026

Sleep well in the summer

We love the warm sunny days with the chance to get outside with our children and enjoy time together. But at the end of a long day playing how can you ensure your child has a good nights sleep in the heat of a sticky bedroom?

Cooling the bedroom

Lighter or no bedding
Light cotton sleep wear
During the day time to help build-up of heat, shut the curtains or blinds and keep the windows closed if the temperature outside is hotter outside than inside. During the night, open the windows if the temperature outside becomes cooler.
Place a fan at a low level near a window to circulate the cooler air at night.
A cool flannel or towel on a fore head or feet. Cool feet help to keep the rest of the body cooler.
A cool shower then rest on top of the bed to dry off – this will help to reduce the body and induce sleepiness
A spray of cool water from a clean plant spray bottle- keep by the bedside to use at bedtime and over night.

Darken the bedroom

Our biological clocks are regulated by light. Getting the balance of enough dark time in the summer months can be difficult. Make sure your child has plenty of exposure to light during the day (not direct sun) and ensure their bedroom is as dark as you possibly make it at night. Darkness triggers the production of the “sleep hormone” melatonin.

Black out blinds are invaluable for blocking out bright morning light and long summer evenings. Try to make sure your child is away from bright light an hour before sleep. This includes all screens and bright bathroom lights too.

Wind down for sleep

Have a wind down time prior to sleep. You should encourage your child to change their activities to something relaxing in the hour or so before bedtime e.g. read to your child or listen to a story tape together.

Clear boundaries

Have clear and consistent boundaries at bedtime, when you say two stories mean two stories, if your child knows what to expect they are less likely to argue.

Bedtime routine

Aim to carry out the same series of steps every night, about 30 minutes before your child goes to bed:

Have a warm relaxing bath lasting about 10 minutes, a pre-bed bath should not be a play time.
Go straight from the bathroom into the bedroom – do not go back into the living area.
Dim the lights: this will help with the production of the sleep hormone melatonin.
Read one to two stories.
Say good night and leave the bedroom.

Your child should be asleep about 15 minutes later.

Bedtime snacks

If your child wants a bedtime snack encourage a snack of foods that contain tryptophan. This amino acid is thought to make some people drowsy such as a banana, warm milk, an oat biscuit, whole grain cereal ,chicken and turkey all contain good levels.

Regular outside exercise

If possible encourage regular periods of outdoor play 20 – 30 minutes three or four times a week. Research has shown increased physical exercise promotes sleep; however aim not to exercise within 3 hours of bedtime.

Praise

Reward children with praise every morning when they have kept to the “rules”. A special trip out or small reward will do wonders do encourage them to keep going.

If you would like help with your child’s sleep please call us 0208 444 0040 or email us for a free assessment.

How to Help Your Baby Sleep Safely in the Heat