The recommended temperature for a baby’s room is 60 to 68°F (16 to 20°C). This range keeps infants comfortable during sleep without raising the risk of overheating, which is linked to sudden infant death syndrome (SIDS). Most parents find the sweet spot is right around 65 to 68°F, which may feel slightly cool to an adult but is ideal for a sleeping baby.
Why Babies Need a Cooler Room
Babies lose and gain heat much faster than adults. Their bodies are small, their skin is thin, and their ability to regulate temperature is still developing. When a baby’s skin temperature drops just one degree below the ideal of 97.7°F, their oxygen use can jump by 10% as their body works harder to generate warmth. The reverse is also true: in a room that’s too warm, a baby can overheat quickly because they can’t cool themselves down as effectively as an older child or adult.
This sensitivity is why the target range is narrow. A room above 68°F (20°C) starts to push into territory where overheating becomes a concern, especially once you factor in clothing and blankets. A room well below 60°F (16°C) forces the baby’s body to burn extra energy staying warm, which is particularly risky for premature or sick infants.
The Link Between Overheating and SIDS
Overheating is a recognized risk factor for SIDS. Research has established a connection between climatic temperature and SIDS incidence, with overheating found to be more common in winter, when parents tend to bundle babies in extra layers and crank up the heat. The risk increases when infants can’t mount an appropriate response to their environment. A baby who is too warm may not rouse from deep sleep the way they normally would, and that failure to arouse is one of the mechanisms researchers believe contributes to SIDS.
The CDC advises not covering a baby’s head and not allowing them to get too hot during sleep. Keeping the room at or below 68°F (20°C) is one of the most straightforward ways to reduce this risk. If you leave the heating on overnight, set the thermostat no higher than 68°F (20°C).
How to Check if Your Baby Is Too Hot
A room thermometer is the easiest tool. Place it near the crib, away from windows and heating vents, to get an accurate reading of the air your baby is actually sleeping in. But the thermometer only tells part of the story. You also need to check your baby directly.
The best spot to feel is the back of the neck or the chest. If the skin there feels hot or sweaty, your baby is too warm. Hands and feet are unreliable because they tend to run cool in young infants regardless of core temperature. Other signs of overheating include:
- Flushed or red skin, especially on the face
- Damp hair
- Fussiness or restlessness
- Rapid heart rate
- Unusual tiredness or sluggishness
Keep in mind that some babies overheat without sweating. If your baby seems unusually lethargic, limp, or is vomiting, those can be signs of heat exhaustion, which needs immediate attention.
What Your Baby Should Wear to Bed
Room temperature alone doesn’t determine whether your baby is comfortable. What they’re wearing matters just as much. Sleep sacks and wearable blankets use a rating system called TOG, which measures thermal resistance. The higher the TOG number, the warmer the garment. Here’s how to match the right TOG to your nursery temperature:
- 75 to 81°F (24 to 27°C): 0.2 TOG, the lightest option. A single layer or just a diaper underneath.
- 68 to 75°F (20 to 24°C): 1.0 TOG. A light sleep sack over a short-sleeve bodysuit.
- 64 to 72°F (18 to 22°C): 1.5 TOG. A medium-weight sleep sack over a bodysuit.
- 61 to 68°F (16 to 20°C): 2.5 TOG. A warmer sleep sack with a long-sleeve layer underneath.
- Below 61°F (16°C): 3.5 TOG. The warmest option, with an extra layer beneath.
You’ll notice these ranges overlap. That’s intentional. A baby at the cooler end of 68°F may do fine in either a 1.0 or 1.5 TOG depending on the layer underneath. Start with the lower TOG option and check your baby’s chest after 20 minutes. If the skin feels cool, add a layer. If it feels warm or clammy, scale back.
Loose blankets, pillows, and stuffed animals don’t belong in the crib. A properly rated sleep sack replaces a blanket safely.
Managing Temperature Through the Seasons
Summer and winter each create their own challenges. In summer, the nursery can climb well above 68°F even with air conditioning. If you can’t get the room below 75°F, dress your baby in the lightest clothing possible (a 0.2 TOG sleep sack or just a onesie) and use a fan to circulate air. A fan doesn’t need to blow directly on the baby. Pointed at a wall or the ceiling, it keeps air moving and prevents heat from pooling around the crib.
Winter is when overheating risk actually peaks. The instinct to pile on layers and turn up the thermostat works against safe sleep. If your home runs cold and you want to keep the heat on overnight, set it to 68°F (20°C) at most and dress your baby in a 2.5 TOG sleep sack with a long-sleeve bodysuit. Resist the urge to add hats indoors. Babies release excess heat through their heads, and covering it traps that heat.
Humidity Matters Too
Temperature gets the most attention, but the moisture level in the air also affects how comfortable and healthy your baby’s sleep environment is. The ideal humidity for a nursery is between 35 and 50 percent. Below 35%, the air becomes dry enough to cause irritated nasal passages, nosebleeds, and dry skin. Above 50%, you’re creating conditions where mold and dust mites thrive, which can trigger coughing and breathing difficulties.
A simple hygrometer (often built into nursery thermometers) tells you where you stand. In dry winter months, a cool-mist humidifier can bring levels up. In humid summers, air conditioning or a dehumidifier keeps things in range. Either way, the goal is the same: air that’s easy for small lungs to breathe.