How to Keep your Baby Cool During a Heatwave

Practical Tips for Parents

When a heatwave hits, parents of young infants often face a daunting challenge: how to keep their baby safe, comfortable, and cool at home. In the UK and Ireland, where residential air conditioning is uncommon and homes are built to retain heat, this can be especially tricky during unexpected hot spells. Babies under 6 months are particularly vulnerable to overheating, their tiny bodies aren’t yet good at regulating temperature and they can’t tell us when they’re too hot. This article provides evidence-based ways to manage heat and keep your baby cool and safe during a heatwave.

Why Babies Struggle in the Heat

Newborns and young infants are sensitive to high temperatures. Unlike adults, babies don’t sweat effectively and can’t cool themselves as easily. In fact, infants produce more body heat relative to their size, and their temperature can rise faster, they retain heat more than adults.

Because babies can’t verbalize discomfort, they rely on us to protect them from overheating. Even a mildly hot day can make a young baby uncomfortable or even ill if proper precautions aren’t taken. Overheating in infants not only causes irritability and dehydration, but is also linked to increased risk of heat exhaustion and even SIDS (Sudden Infant Death Syndrome) in severe cases. Understanding their vulnerability is the first step to keeping them safe.

Creating a Cool Home Environment (Without A/C)

1. Keep the Heat Out: During the hottest part of the day, close curtains or blinds on windows to block direct sun and keep the room cooler. Light-blocking or thermal curtains can help reduce incoming heat. In the evening or early morning when outside air is cooler than indoors, open windows (if safe to do so) to let in a breeze and ventilate. Many UK/Ireland homes trap heat, so using the cooler night air can bring the temperature down.

2. Encourage Airflow: If you have a fan, use it to circulate air in the room, but do not point it directly at the baby. A direct fan can actually dehydrate infants by blowing away moisture and can make them too cold or uncomfortable. Instead, position the fan to oscillate or direct it toward a wall or ceiling, just to keep air moving. A useful trick is placing a bowl of ice water in front of a fan to cool the airflow slightly (essentially a DIY cooler). Always keep fans and cords well out of baby’s reach for safety. If your home has multiple floors, remember that lower floors (like the ground floor) tend to stay cooler than upstairs, it might help to spend more time downstairs during peak heat.

3. Cool Rooms Strategically: Identify the coolest room in the house (often a north-facing room or one on the shade side) and consider setting up your baby’s cot or a safe play area there during the day. Remove any unnecessary padding or cot bumpers that can restrict airflow around the cot. Using light cotton curtains or blinds to block sunlight while allowing some air through can keep that room more bearable.

4. Mind the Indoor Temperature: It’s wise to monitor the room temperature where your baby sleeps. A nursery thermometer is handy, the ideal sleep environment for an infant is about 17 –20 °C. If your home is warmer than this, take the other steps in this guide to bring the temperature down. Never place a baby’s cot next to a direct heat source (radiator, heater, or sunny window). And never, ever leave your baby in a closed, parked car or unventilated space, even for a few minutes, temperatures can skyrocket quickly and become life-threatening.

Dress Lightly: Clothing and Bedding Tips

When it’s sweltering, less is more in terms of baby clothing. Keep your baby in lightweight, loose-fitting outfits or sometimes just a nappy to prevent overheating. Cotton is an ideal fabric in hot weather as it’s breathable and absorbs sweat, helping cooling by evaporation. Avoid synthetic fabrics that can trap heat and irritate the skin.

For newborns and infants under 6 months, it’s usually sufficient to dress them in a short-sleeved vest or just a nappy when indoors if it’s very warm. Check your baby’s skin for signs of heat rash (small red bumps, often on the neck, back, or creases); loose cotton clothing can help prevent and ease prickly heat rashes.

Bedding: Ditch heavy blankets and quilts in hot weather. Use a light cotton sheet or a low-tog baby sleeping bag (0.5 tog if available) with no padding. Often, you won’t need any covering at all besides perhaps a thin muslin or sheet over a nappy-clad baby. Do not use hats or bonnets on your baby when indoors or sleeping, babies cool themselves through their head, and wearing a hat can cause overheating during sleep (Hats are useful right after birth or outdoors for sun protection, but not for sleep in hot weather.)

At night, if it’s very warm (over ~25 °C in the room), many babies will be fine sleeping in just a nappy and perhaps a sleeveless bodysuit. Keep nightwear to a minimum and remove any extra bedding if the baby is warm or sweaty. You can always add a lightweight layer later in the night if temperatures drop. Remember that babies sleep most comfortably when their environment is on the cooler side of our comfort range a too-warm baby will be restless and at risk of overheating.

Hydration and Feeding in Hot Weather

Keeping your baby well-hydrated is critical during a heatwave. For infants under 6 months, breast milk or formula provides all the hydration they need; do not give water to young babies (unless directed by a paediatrician) because it can upset their electrolyte balance and fill their tummy improperly; never dilute formula or give infants other liquids like juice etc. Instead, offer extra feeds on demand. Breastfed babies may want to nurse more frequently in hot weather, even if for shorter durations, this is normal and helps them stay hydrated. Breast milk adapts in hot weather; your body may produce slightly thinner milk for thirst-quenching. If you are breastfeeding, make sure you drink plenty of fluids as well, staying hydrated helps you maintain your milk supply.

Watch for dehydration signs: Check that your baby has regular wet nappies. A well-hydrated infant should have 6–8 pale wet nappies in 24 hours. If you notice fewer wet nappies, or the urine is dark and concentrated, it’s a sign the baby needs more fluids. Other dehydration signs can include a dry, sticky mouth, and extreme fussiness or lethargy. If your baby is refusing to feed, seems very listless, or has sunken eyes or a sunken soft spot, seek medical advice, these can be signs of dehydration or heat illness.

Feeding comfort: Skin-to-skin contact can make both you and baby sweaty in the heat. When nursing or bottle-feeding, you might place a light cotton sheet or towel between you and the baby to reduce skin contact and keep you both a bit cooler. Try feeding in the coolest room available, and ensure good airflow in that area.

Safe Sleep During a Heatwave

Keeping your baby cool at night is not only about comfort, it’s also about safety. Overheating has been linked to a higher risk of SIDS, so safe sleep guidelines become especially important in hot weather. Here’s how to ensure safe, cool sleep:

• Cool the room before sleep: In the evening, ventilate the nursery or bedroom by opening windows (if outside air is cooler) and using a fan to circulate air (remember: indirect flow only). You might even give your baby a lukewarm bath before bedtime to cool their body temperature slightly, many parents find this helps baby settle in the heat. (The bath water should be tepid, not cold)

• Minimal sleepwear: Dress your infant in minimal clothing for bed, a simple short-sleeve vest or just a nappy can be enough if the room is very warm. Remove any thick bedding; a single light sheet or an empty cot with just the mattress and a well-fitted sheet is safest. Do not use bulky blankets, duvets, or pillows around a young baby, as these can cause overheating and pose a suffocation risk. A light cellular cotton blanket (with tiny breathable holes) can be used if needed – these allow airflow and are safer for temperature regulation.

• Cot placement: Position the cot or Moses basket in the coolest part of the room, away from direct sunlight. Never place a baby’s cot next to a radiator or heater, or in direct line of a fan or air conditioning vent. Also, avoid leaving baby to sleep in a pram or car seat during hot weather, especially in an enclosed space. A pram can become like a little greenhouse, even more so if covered with any cloth. Transfer baby to a properly ventilated cot for sleep whenever possible.

• Head and face uncovered: Make sure your baby’s head remains uncovered during sleep. This means no hats or hoods, and keeping blankets away from the face. Babies release heat from their heads to cool down; blocking that can lead to overheating. If you swaddle your baby normally, consider that swaddling is not recommended in hot weather or use a very thin cotton muslin and ensure the room is cool. Many families skip swaddling during a heatwave to prevent trapping too much warmth.

• Check on them: It’s wise to check your baby’s temperature by feeling their tummy or back of neck periodically. The skin should feel comfortably warm, not hot, sweaty, or cold. If baby feels hot to the touch, or if you observe sweating, remove a layer of clothing or bedding and consider increasing air circulation. A touch test on baby’s hands or feet isn’t reliable (babies’ extremities often feel cool even when they are too warm), always check the core (tummy/back) for a true reading.

Expect that your infant’s sleep pattern might change in hot weather. They might wake more often due to discomfort or conversely seem extra sleepy from the heat during the day. Be flexible, if they take an extra nap or drink more at night, that’s okay during a heatwave. Prioritize keeping them cool and hydrated, and resume normal routines when the weather moderates.

How to Recognize Overheating: Signs & Symptoms

It’s crucial to be able to tell when your baby is becoming too hot. An overheating baby may show one or more of these warning signs:

• Excessive warmth or sweating: The baby’s skin may feel hot to the touch, especially on the chest or back, and you might notice damp hair or sweat on their neck/back. Sweating is a key sign (though infants may not always sweat a lot, so don’t rely on sweat alone. If a baby is drenched in sweat or has a sweaty head/neck, they are too hot.

• Flushed skin or heat rash: Many babies develop a red, flushed face when overheated, or you might see a blotchy red rash of tiny bumps (heat rash, also called prickly heat) on their skin. The rash often appears on the neck, chest, or nappy area in response to sweating. On the other hand, some babies’ skin might appear pale with cool, clammy sweat, then turn red and warm as heat stress worsens.

• Irritability or lethargy: An overheated baby might be unusually fussy, crying, and unable to be comforted, or, conversely, unusually drowsy, listless, or floppy. If your baby who is normally alert becomes sluggish or hard to wake, that’s a serious red flag. Overheating can make babies very sleepy or even dizzy, as their bodies struggle with the heat.

• Rapid breathing or heart rate: You may notice your baby breathing fast or panting when too hot. Their heart rate may also be elevated. A bright red tongue or dry mouth can accompany this if they’re becoming dehydrated. Always ensure they are getting enough fluids (via milk feeds) to support their cooling.

• Fewer wet nappies and other dehydration signs: As mentioned, if the baby isn’t getting enough liquid, dehydration can set in. Fewer than 6 wet nappies in 24 hours, dark urine, a sunken soft spot on the head, or no tears when crying are signs of dehydration and possible heat stress. The baby may also have a dry or sticky mouth. In heat, keep track of those diaper counts!

• Severe symptoms (medical emergency): In extreme cases, overheating can progress to heat exhaustion or heatstroke. Signs include very high body temperature (baby feels very hot, possibly with a fever > 39–40 °C), vomiting, fast breathing, or unresponsiveness, or even seizures. The skin may be hot and dry to the touch if sweat mechanisms have shutdown. If your infant ever shows these signs, treat it as an emergency, move the baby to a cooler area immediately, begin gentle cooling measures (see below), and seek medical help right away.

What to do if you suspect overheating: At the first sign your baby is too hot, act quickly to cool them down. Move to a cooler space out of direct heat (indoors or at least in shade), remove excess clothing, and encourage hydration (offer breast or bottle). You can sponge the baby with lukewarm water or give a tepid bath to help lower their temperature gradually. Never use icy cold water or a cold bath, as cooling too fast can be a shock, gentle, lukewarm water is effective and safe. You can also use a soft fan breeze nearby (not directly on them) to aid evaporation from their damp skin. If the baby’s condition doesn’t improve quickly with these measures, or if they display any severe symptoms, get medical attention promptly. Trust your instincts: it’s better to be cautious and seek help if you’re worried.

Heatwave Safety: What Not to Do

Just as important as the do’s are the don’ts. Avoid these common mistakes that could put your baby at risk during hot weather:

• DON’T cool too quickly or with extreme cold: Plunging a baby in a very cold bath or shower, or applying ice packs, is not a safe way to cool them. Sudden cold can constrict their blood vessels and actually raise core temperature. Instead, use lukewarm water for baths or sponging, which is effective without the shock. Similarly, never rub alcohol on a baby’s skin to cool them (an old folk remedy), it’s dangerous. Cool water and air circulation are safest.

• DON’T point fans directly at baby: As noted earlier, a fan blowing straight on an infant can overly dry and cool them, or dehydrate them by increasing moisture loss. Always ensure any cooling breeze is indirect. Also keep the fan a safe distance away and out of reach.

• DON’T cover the pram with a blanket or heavy cover: It might be tempting to drape a muslin or blanket over a stroller to shield baby from sun, but doing so can turn the pram into an oven. Even a thin cloth greatly reduces air circulation and traps heat inside, causing temperatures to soar dangerously. Use a parasol or sunshade attachment for the pram instead, or stick to the shade. And never leave your baby sleeping in a covered pram in hot weather they are much safer in a cot indoors or another ventilated space.

• DON’T leave baby in a parked car or enclosed space: This is a life-threatening hazard. Cars can heat up by several degrees per minute in the sun. Even five minutes in a hot car can be extremely dangerous for an infant. Always take your baby with you and never risk it. Likewise, avoid tight enclosed spaces like small rooms with no air flow.

• DON’T overdress or use too much bedding: Resist the urge to “be on the safe side” by adding an extra layer, in heat, the risk is being too warm, not too cold. Remove any waterproof mattress protectors (they hold heat and sweat). No duvets, quilts, or pillows around the baby. And remember, no hats during sleep and no mittens or socks if it’s very hot; those trap heat.

• DON’T give water (or juice) to young babies instead of milk: As mentioned, babies under 6 months should not be drinking water as their kidneys can’t handle it well. Water also fills them up with no calories, which can lead to less feeding and potential electrolyte imbalances. Stick to breast milk or formula, and just offer it more often.

• DON’T ignore warning signs: If your baby seems off, for example, unusually quiet, excessively irritable, or not feeding, don’t just assume they’re “fine.” Babies can go downhill quickly in extreme heat. Check their temperature (feel their torso), try to cool them, and if you’re unsure, call a health professional for advice. Do not give fever-reducing medicine to a baby for heat stress without medical advice; if a baby is overheated from the environment, the solution is cooling and hydration, not medication (unless directed by a doctor).

(Sources: NHS, HSE Ireland, American Academy of Pediatrics, Pregnancy Birth & Baby Australia, UNICEF)

Final Thoughts

Heatwaves can be challenging with a young baby, but with some proactive steps you can keep your little one cool, safe, and as comfortable as possible. Stay calm and pay attention to your baby’s cues. Often, keeping a baby cool is about simple measures: find the coolest spot, undress them, offer extra feeds, and chill out together until the heat passes. By using the tips above – and avoiding the common hazards – you’ll be well prepared to protect your baby during hot days.