Ireland does not get hot very often, so when it does, nobody is ready. Our houses are built to hold heat in, not let it out, and a stuffy box room can stay warm long after the evening has cooled down. A baby feels all of that more than you do, because they cannot regulate their own temperature well and they cannot kick off a blanket or tell you they are too warm.
You do not need a Mediterranean heatwave for this to matter. A bright Irish day in the high twenties is plenty to overheat a baby. Here is the plain version of how to keep them cool and safe, day and night, based on HSE guidance.
How warm should the room be
The HSE recommends keeping the room where your baby sleeps at 16 to 20 degrees. A cheap room thermometer is the easiest way to actually know, rather than guessing off how the room feels to you (you are dressed differently and moving around).
This matters more than just comfort. Overheating raises the risk of cot death, also called sudden infant death syndrome. A baby can get too hot from too much bedding or clothing, or simply because the room itself is too warm. Keeping the room in that range, and dressing them lightly, is one of the safe-sleep basics.
What to put them in for sleep
The instinct on a warm night is to strip them right back, and that instinct is roughly right. The HSE line is that a nappy, a vest and a babygrow are enough, and you should use less clothing in warmer weather. On a genuinely hot night, a nappy and a vest may be all they need.
For covering, a low tog sleeveless baby sleeping bag is easier to get right than blankets, because there is nothing to ride up over their face and you are not constantly re-tucking. If you do use blankets, thin cotton cellular ones are best, the kind with the little holes that let air move through. And the usual safe-sleep rule still holds in summer.
- No duvets, quilts, pillows, cot bumpers or soft toys
- A firm, flat mattress, baby on their back, feet to the foot of the cot
- A low tog sleeveless sleeping bag, or thin cellular blankets, never heavy bedding
- Never put the cot beside a radiator, heater or in direct sunlight
How to tell if your baby is too hot
Hands and feet are a red herring. A baby's hands are often cool even when the rest of them is toasty, so do not judge by them. Instead, slip a hand onto their chest, tummy or the back of the neck. It should feel warm, not hot or sweaty.
Other signs they are overheating:
- Sweating, or damp hair
- Flushed or red cheeks
- Breathing faster than usual
- Restless, or unusually drowsy and hard to rouse
If they feel too warm, take a layer off, move them somewhere cooler and offer a feed. You are not aiming for cold, just not hot.
Cooling the room down
You can do a lot with curtains and timing. During the day, keep the blinds or curtains closed on any window the sun hits, to stop the room heating up in the first place. Then, when the air outside cools in the evening, open windows where it is safe to do so to let the warm air out.
A fan helps move the air around. The HSE notes a fan is useful when the temperature is below 35 degrees, which in Ireland it almost always is. Aim it across the room rather than straight at your baby, and a bowl of water in front of it gives a little extra cool. A lukewarm bath before bed is another simple way to bring their temperature down before sleep.
Out and about: the pram and the sun
The big summer mistake is draping a muslin or blanket over the pram to make shade. It feels protective and it does the opposite. A cloth over the hood traps heat and stops air moving, and the inside can climb to a dangerous temperature very quickly. Use the pram's own sunshade and never cover it over completely. Air needs to circulate.
On the sun itself, the HSE is clear: keep babies under 6 months out of direct sunlight altogether, using shade and clothing rather than sunscreen. For babies under 12 months, stay in the shade, dress them in light clothing that covers their skin, add a wide-brimmed hat, and keep the buggy sunshade up. We go through all of this properly in our guide to sun safety for babies.
The car: the one that catches people out
This is the most important paragraph on the page. Never leave your baby alone in a car, even for a minute, even in the shade, even with a window open. A parked car can heat up by at least 10 degrees in just ten minutes, and a cracked window does not keep it cool enough. Babies heat up far faster than adults do. If you are nipping into a shop, the baby comes with you, every time.
Keeping them hydrated
For a baby under 6 months, the answer to hot weather is not water, it is more frequent milk feeds. Offer the breast or their usual formula more often than normal, and they will take what they need. Breastfed babies do not need any extra water at all, even in a heatwave. There is a common question hidden in here, and we answer it in full in does a breastfed baby need water in hot weather.
Keep an eye on wet nappies as your hydration gauge. The HSE flags these as signs a baby is becoming dehydrated and needs help:
If your baby does get too hot
If they have overheated, cool them down quickly: bring them indoors or into the shade, take off the extra clothing, and sponge their skin with cool (not cold) water. If they are awake and behaving normally, offer a feed or a drink. Heat exhaustion can tip into heatstroke, which is a medical emergency, so if a baby is very hot and becomes drowsy, floppy, or is not responding as normal, call 112 or 999. The HSE has more on heat exhaustion and heatstroke in children.
Worth a quick check before a hot spell
Met Éireann issues colour-coded high temperature warnings when a hot spell is coming, and they point out that warm nights can be harder on small children than warm days. If a yellow or orange heat warning is forecast, that is your cue to sort the bedroom out before bedtime, not after. You can check live warnings at Met Éireann.
The short version
- Sleep room at 16 to 20 degrees, checked with a thermometer
- Less clothing, low tog sleeping bag, no heavy bedding
- Check the chest or back of the neck, not the hands
- Curtains closed by day, windows open when it cools, fan across the room
- Pram sunshade up, never a cloth over the hood, under 6 months out of direct sun
- Never leave a baby in a parked car, for any length of time
- More frequent feeds, and watch the wet nappies
For the full safe-sleep picture year round, see the HSE page on your baby's sleep temperature.
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