It’s better for babies to sleep in a cooler room
The question often comes up, what room temperature should a baby sleep in, and parents’ opinions vary. Some ask their health visitor or GP, or read the guidance, and try to create the optimal sleep environment for their child.
Others trust their own judgement, letting the temperature vary across a wider range and adjusting what the child wears to suit the changes.
We would like to answer in a way that helps both approaches. Some people prefer to follow recommendations, others rely on their own senses to create the best setting for their baby. There are also families who want to follow professional advice, but cannot control heating at home, so they need other ways to balance things out.
The right temperature for baby sleep is 20 to 22°C H2
While a comfortable daytime temperature works well for us and for babies, for sleep most guidance suggests a slightly cooler room, ideally around 20 to 22°C. Cooler air can make sleep more restful.
At a lower temperature you can avoid sweating, startling awake and night time wakings. Many of us have experienced this ourselves.
The body has a rhythm that shifts core temperature during sleep. From about three months, your baby’s rhythm becomes more regular, similar to an adult’s. In the evening and at sleep onset the body cools a little, then warms towards the early hours and morning. If the room is too warm, that early morning warming can make your baby sweaty and disturb their sleep.
If a room is overheated, the whole family can struggle to fall asleep and overall sleep quality drops. If the air is too cold, circulation to little hands and feet is reduced, the body cools, and mucous membranes are less protected, which can lead to a runny nose, sore throat and cough.
Newborns have different temperature needs
Newborns cannot regulate body temperature well yet, and cannot balance environmental effects either. For around the first month, choose a slightly warmer room, about 22 to 24°C, and dress them a bit more warmly.
What if you cannot control the heating
If you cannot adjust the heating and it is very warm indoors in winter, say 23 to 24°C, there are a few ways to cool the air. A common, if wasteful, method is to keep a window slightly open so the cooler outdoor air takes effect.
The plus side is a supply of fresh air, provided you are not beside a busy or dusty road, and you can keep a fairly steady, comfortable temperature.
Do not open a window directly onto the baby. Instead, choose a room from which the cooler air can flow gently towards the nursery.
Many homes now have air conditioning that keeps temperatures even. Some children are sensitive to it, so it helps if the unit is as far from the cot as possible.
Whichever method you use, always make sure the baby is not in a draught and is not exposed to direct cold airflow.
Spring and autumn, when the heating is off
You can run into trouble when daytime temperatures are higher than the early hours. This is common in autumn and spring when there are big day to night swings and the heating is off. With solid fuel systems you can see the same in winter, evening stoking raises the heat quickly, then it cools overnight.
If you can choose when to start overnight heating in autumn, you can regulate the temperature, which is ideal. If not, rely mainly on layering at bedtime and a little evening airing.
Here is a simple tip from a mum for when evenings are warmer but the air cools by dawn:
“In the evening I put my child down in a onesie, then I laid out the sleeping bag open on the changing table. During the night feed, when they woke, I slipped them into the sleeping bag and settled them back down. That way they did not get cold at dawn when the room cooled.”
Temperature differences between rooms
If you can, set the temperatures in the rooms your baby goes into so there are no big jumps between them. Sudden cold can be a problem, and draughts or the feeling of airflow can be stronger if rooms differ a lot. Keep your baby where there is no strong air movement, no air conditioner blowing, and no draught.
Dressing babies for sleep
Because what babies should wear for sleep is such an important topic, we have written a full article about it. You will learn about babies’ temperature regulation, the normal range, how night time body temperature changes, and the signs that your child is chilly or too warm.
Reference to our previous article, title: What should a baby wear for sleep.
Humidity
Since humidity links closely with air temperature, it is worth mentioning.
For healthy adults, 40 to 60 percent humidity is optimal. For children this is higher, 60 to 70 percent. Humidity affects how warm we feel, higher feels warmer, lower feels cooler.
Why is low humidity a problem
Because mucous membranes dry out more easily, which can cause irritation, scratchy throat, dry eyes and mouth, and a dry cough. If the mucosa cannot offer enough protection against pathogens, babies may fall ill more often.
Do not go to extremes
Very high humidity favours the growth of pathogens and mould, especially in older buildings with musty air.
Aim for the right level
If needed, humidify. Drying laundry indoors can help, provided you choose detergents carefully. Remember that detergents and fabric softeners contain chemicals. As clothes dry indoors, these evaporate into the room air, which your baby and family breathe every day.
Choose natural detergents, and you can use vinegar as a softener, which disinfects, softens and leaves a fresh scent.
If humidity runs high, improve it with regular airing or a dehumidifier.
Did you know
Recommendations for sleep temperature vary by culture. In some European countries 18 to 19°C is considered ideal. Northern nations are typically more accustomed to cooler air, and often let babies nap outside in prams in the cold. For them this is perfectly normal.
Sources:
NHS — Reduce the risk of sudden infant death syndrome. Guidance includes keeping the room around 16 to 20°C and avoiding overheating
The Lullaby Trust — Your baby’s room temperature. Practical safer sleep advice on keeping babies comfortable and not too hot
