Baby Room Temperature: Is Your Nursery Too Hot or Too Cold?

Key Takeaways

• Around 20–22°C (68–72°F) is a sensible temperature to aim for in a baby’s room, but there is no single temperature that is right for every baby or every home.
• Overheating is more important to avoid than trying to keep the room at an exact temperature. Check your baby as well as the room temperature, looking for signs such as sweating, flushed or hot skin, or a hot chest.
• The temperature around your baby’s sleeping space can differ from the room temperature. Drafts, windows, radiators, sunlight, ventilation, humidity, clothing and bedding can all affect the conditions around the cot.
• Dress your baby according to the conditions rather than relying on heavy bedding. A wearable blanket or appropriate sleep clothing can provide warmth without adding loose items to the sleep space.

 

Getting the temperature right can make a big difference to your baby’s comfort during sleep. It is also important for safer sleep: overheating has been associated with an increased risk of SIDS, so babies should not be overdressed or exposed to excessive heat.

But how do you know whether your nursery is too hot or too cold?

What is the ideal temperature for a baby’s room?

Around 20–22°C (68–72°F) is a sensible temperature to aim for in a baby’s room. This range is also used in the U.S. NIH/NICHD Safe to Sleep® educational guidance. However, U.S. health authorities do not treat a particular temperature as a strict safety threshold. Their advice is to keep the room comfortable and, most importantly, avoid overheating.

That means a room thermometer is useful, but it is not the whole answer. Your baby can still be too hot or too cold even when the room reads 20–22°C. The cot’s position, drafts, radiators, sunlight, ventilation, clothing and bedding can all change the temperature your baby actually experiences. So look at the whole sleeping environment, not just the number on the thermometer.

Is the nursery too cold? Here are 5 things to check

If the room feels cold, look for the factors that may be lowering the temperature around your baby’s sleeping space.

Drafts, windows and exterior walls

Cold air coming through windows, doors or poorly insulated areas can make the space around the cot colder than the rest of the room. A cot positioned close to a cold window or exterior wall may also be exposed to lower temperatures. Where possible, keep the sleeping space away from noticeable drafts and particularly cold surfaces.

Humidity

High humidity can make the air feel colder, even when the room temperature itself has not changed. This can be especially noticeable during periods of damp or rainy weather. If the room feels unusually cold or damp, check both the temperature and humidity rather than relying on temperature alone.

Insufficient heating

A room can become significantly colder during the night, particularly in winter. Check the temperature when your baby goes to sleep and again later if your home tends to cool down overnight.

Lightweight clothing or bedding that is not enough for the conditions

If the room is slightly below the recommended range, you may need to add one lightweight layer of clothing or adjust the sleeping bag according to the manufacturer’s guidance. Avoid compensating with thick or heavy blankets.

A sudden change in weather

A sudden cold spell, snowfall or drop in temperature can change the conditions in your baby’s room very quickly, even if you normally keep it at a comfortable temperature. During sudden changes in weather, check the room temperature again and pay attention to how your baby’s sleeping space feels. You may need to adjust heating, ventilation or sleep clothing to keep the environment comfortable.

Is the nursery too hot? 5 things to check

Overheating can happen even when the room temperature itself does not seem particularly high.

Direct sunlight

Sunlight coming through a window can quickly heat up a nursery and the area around the cot. Keep curtains or blinds closed during the hottest part of the day when necessary, particularly in summer.

Radiators and heaters

The cot should not be placed next to a radiator, heater or fire. These can create a much warmer environment around the baby than the general room temperature suggests.

Too many layers or heavy bedding

Several layers of clothing, thick blankets or padded bedding can trap heat and make a baby too warm, even when the room temperature is comfortable. Dress your baby according to the temperature and use lightweight bedding or an appropriate baby sleeping bag rather than adding unnecessary layers.

High humidity

Hot, humid conditions can make a room feel considerably warmer and less comfortable. Humid air can also make it harder for the body to lose heat through evaporation. A cool, well-ventilated room with moderate humidity is generally more comfortable for sleep than a room that is both hot and humid.

Poor ventilation and hot air

A closed room can become considerably warmer overnight, particularly during hot weather. If it is safe to do so, opening a window or door can help air circulate. A fan can also help cool the room, but it should not be directed directly at the baby.

The room temperature can be right, but the cot can still feel too hot

A room thermometer may show 18°C, but the temperature immediately around your baby can be different.

The cot’s position, the mattress, bedding, clothing, nearby heat sources, sunlight and airflow can all affect the temperature of the sleeping space. This means that room temperature and sleeping-space temperature are related, but they are not necessarily the same.

You should check your baby rather than relying only on a room thermometer. The chest or back of the neck is a better indication of whether your baby is too warm than their hands or feet, which are often cooler normally. If your baby’s skin is hot or sweaty, remove a layer.

How should you dress your baby for sleep?

There is no single outfit that is right for every temperature or every baby.

As a general rule, you should dress your baby according to the room and sleeping-space temperature, using lightweight layers rather than heavy bedding.

If you use a baby sleeping bag, follow the manufacturer’s guidance for the appropriate tog rating and clothing underneath it.

If you use blankets, choose lightweight bedding rather than thick, fleecy or padded blankets.

Also, your baby does not need a hat for indoor sleep. Hats can contribute to overheating, so the U.S. National Institutes of Health’s Safe to Sleep® program recommends removing a baby’s hat when indoors.

And remember: cool hands and feet do not necessarily mean that your baby is cold. Check the chest or back of the neck instead.

How can a sleep monitor help?

A sleep monitor that measures temperature in the cot, including monitors positioned under the flat sheet, can give you a more direct indication of the temperature in your baby’s sleeping space.

As seasons change, this can help you decide whether your baby may need more or fewer layers to remain comfortable.

Some sleep monitors can also provide an alert if the temperature becomes too high or too low, allowing you to check the sleeping environment and make adjustments when needed.

A temperature monitor does not replace safe-sleep practices or checking your baby. It simply gives you another useful piece of information about the environment in which your baby is sleeping.