The ideal house temperature for a newborn is between 68 and 72°F (20 to 22°C). This range keeps your baby comfortable without increasing the risk of overheating, which is a known contributor to Sudden Infant Death Syndrome (SIDS). Getting the temperature right matters more than many new parents realize, but it’s straightforward once you know what to aim for.
Why This Temperature Range Matters
Newborns can’t regulate their body temperature the way adults can. They lose heat quickly through their skin, and they also struggle to cool themselves down when things get too warm. Unlike older children and adults, young infants can’t sweat effectively, which means they can develop heat-related illness much faster than you might expect. A room that feels perfectly comfortable to you in a sweatshirt could be too warm for a swaddled baby.
Overheating during sleep is directly linked to a higher risk of SIDS. The connection is well established enough that the American Academy of Pediatrics includes it in their safe sleep guidelines. Keeping the room between 68 and 72°F hits the sweet spot: warm enough that your baby doesn’t need loose blankets (which pose their own suffocation risk) but cool enough to avoid overheating.
How to Dress Your Baby for the Room Temperature
The room temperature only tells half the story. What your baby wears to bed matters just as much. Sleep sacks (wearable blankets) are rated by a measurement called TOG, which indicates how much warmth they provide. Matching the right TOG to your room temperature keeps your baby comfortable without piling on layers or using loose bedding.
- 75 to 81°F: A lightweight 0.2 TOG sleep sack, or just a onesie
- 68 to 75°F: A 1.0 TOG sleep sack over a onesie
- 64 to 72°F: A 1.5 TOG sleep sack, possibly with a long-sleeve layer underneath
- 61 to 68°F: A 2.5 TOG sleep sack with a warm base layer
- Below 61°F: A 3.5 TOG sleep sack with warm pajamas underneath
A good rule of thumb: dress your baby in one more layer than you’d wear comfortably in the same room. Skip hats indoors. Covering your baby’s head while sleeping traps heat and raises the risk of overheating.
Using a Fan Reduces SIDS Risk Significantly
One of the most striking findings in infant sleep safety research comes from a study on room fans. Having a fan on during sleep was associated with a 72% decrease in SIDS risk compared to rooms with no fan. In rooms warmer than 69°F, that decrease jumped to 94%. The fan doesn’t need to blow directly on the baby. Gentle air circulation throughout the room helps prevent pockets of stale, rebreathed air from forming around your baby’s face, which is thought to be one of the mechanisms behind SIDS.
A ceiling fan on a low setting works well. So does a small room fan pointed away from the crib. The goal is airflow in the room, not a breeze on your baby’s skin.
Where to Place the Crib
Even if your thermostat reads 70°F, the temperature around your baby’s crib can vary depending on its location. Place the crib in the most consistently warm part of the room, away from drafty windows and heating vents. Being near a heating vent can create hot spots that push the temperature well above what the thermostat shows, while a drafty window can make things colder than expected. If you’re unsure, a simple room thermometer placed near the crib gives you a more accurate read than the thermostat on the wall down the hallway.
Signs Your Baby Is Too Hot or Too Cold
Cold hands and feet are normal in newborns and don’t necessarily mean your baby is cold. The spot to check is the back of the neck or the chest. If the skin there feels warm and dry, your baby is comfortable. If it feels hot or damp, they’re too warm. If it feels cool to the touch, they need another layer.
Signs of overheating include skin that feels very warm, flushed cheeks, rapid breathing, and general fussiness. Because infants can’t sweat well, they may not show the obvious signs of being too hot that you’d see in an older child. Sometimes a baby who’s overheating just looks unwell or unusually irritable. If you notice any of these signs, remove a layer and check again in a few minutes.
A baby who is genuinely too cold will have bright red skin that feels cold to the touch and may seem unusually still or low-energy. This is rare indoors at normal household temperatures but can happen if heating fails or temperatures drop sharply overnight.
Premature Babies Need Extra Warmth
If your baby was born prematurely or at a low birth weight, the standard 68 to 72°F range may not be warm enough. Preterm infants lose heat faster than full-term babies for several reasons: they have less body fat for insulation, thinner skin, and a larger surface area relative to their body weight. They also tend to lie with their arms and legs extended rather than curled up, which exposes more skin to the air.
Your baby’s care team will give you specific guidance before discharge, but in general, keeping the room at the warmer end of the range (72°F or slightly above) and using an extra layer of clothing is a reasonable starting point. Pay close attention to the neck and chest check described above, and adjust from there.
Humidity and Winter Heating
Temperature isn’t the only environmental factor worth monitoring. Humidity in your baby’s room should stay between 35 and 50%. Air that’s too dry or too humid can make your baby cough and have difficulty breathing. Winter heating tends to dry indoor air significantly, so a cool-mist humidifier in the nursery can help keep things in range. A simple hygrometer (humidity gauge) costs a few dollars and takes the guesswork out of it.
In winter, the temptation is to crank the heat and bundle your baby up. Resist both. Set your thermostat to the 68 to 72°F range and use a sleep sack with the appropriate TOG rating instead of adding blankets. If your home has radiators or space heaters, keep them well away from the crib and never leave a portable heater running unattended in your baby’s room.