A room temperature of 67°F (19.4°C) is not too cold for a baby’s room. It actually falls squarely within the range most pediatric safety organizations recommend for infant sleep, which is 68°F to 72°F (20°C to 22°C), and slightly cool rooms are considered safer than warm ones. The bigger risk with nursery temperature is overheating, not a room that’s a few degrees below 70.
Why Slightly Cool Is Safer
Overheating is a well-established risk factor for Sudden Infant Death Syndrome (SIDS). A large study analyzing over 60,000 SIDS cases in the United States between 1972 and 2006 found that in summer months, every 10°F increase in daily temperature was associated with an 8.6% increase in SIDS risk. The risk was even more pronounced for certain groups: infants between 3 and 11 months old faced a 17% increased risk per 10°F rise, and Black infants in that age range had a 24% increased risk.
In winter, the relationship actually reversed. A 10°F increase in temperature was linked to a slight decrease in SIDS risk, likely because extremely cold environments carry their own dangers. But the overall takeaway from the evidence is clear: babies are more vulnerable to warmth than to mild coolness. A room at 67°F keeps your baby comfortably on the safe side of that equation.
The Recommended Temperature Range
Most guidelines suggest keeping the nursery between 61°F and 72°F (16°C to 22°C). The Lullaby Trust, one of the UK’s leading safe-sleep organizations, advises that if you leave heating on overnight, it should be set no higher than 68°F (20°C). At 67°F, your baby’s room is one degree below that ceiling, which is ideal.
The key principle is that babies regulate body heat less efficiently than adults. They can’t kick off blankets or pull one on, and they lose heat through their heads quickly. A room that feels slightly cool to you as an adult is generally perfect for a sleeping infant, as long as they’re dressed appropriately.
How to Dress Your Baby at 67°F
The right clothing makes more difference than bumping up the thermostat. At 67°F, a sleep sack with a 2.5 TOG rating is a good fit. TOG is a measure of thermal resistance, essentially how warm a fabric keeps the wearer. A 2.5 TOG sleep sack is designed for room temperatures between 61°F and 68°F, so 67°F lands right in its sweet spot.
Underneath the sleep sack, a long-sleeved bodysuit or a lightweight cotton onesie is typically enough. If the room dips closer to 64°F or 65°F, you could add a thin layer underneath, like a cotton undershirt. Avoid layering multiple sleep sacks or swaddles on top of each other, as this increases the risk of overheating and suffocation. Choose one appropriately rated sleep garment and adjust the clothing layers beneath it instead.
Every baby runs a little different. Some sleep warm, some sleep cool. The best way to check is to feel the back of your baby’s neck or their chest. If the skin feels warm and dry, they’re comfortable. If it feels sweaty or hot, remove a layer. If it feels cool to the touch, add one. Hands and feet tend to feel cool on babies regardless, so they’re not a reliable indicator.
Keeping the Temperature Consistent
Room temperature can shift through the night, especially in older homes or rooms with poor insulation. A simple room thermometer placed near the crib (but out of baby’s reach) gives you an accurate read. The Lullaby Trust specifically recommends using a room thermometer rather than guessing, since adults perceive temperature differently than infants experience it.
A few practical tips for keeping the nursery stable at night:
- Keep the crib away from heat sources. Radiators, space heaters, heating vents, and direct sunlight can all create a pocket of warmer air around the baby, even when the rest of the room reads 67°F.
- Set a thermostat rather than running a portable heater. If you feel the room is too cold and want to use heating overnight, a thermostat set to a low temperature gives you consistent, predictable warmth. Space heaters near a crib pose burn and fire risks.
- Crack a door or window if the room runs warm. In summer or in well-insulated homes, nurseries can trap heat. A slightly open door improves airflow without creating a draft on the crib.
When a Room Actually Is Too Cold
While 67°F is perfectly fine, rooms that drop well below 61°F (16°C) can become uncomfortable and potentially risky for a baby, particularly a newborn. Signs that your baby is too cold include fussiness, lethargy, and skin on the chest or back that feels noticeably cool. Mottled or bluish skin on the arms and legs is a sign the baby needs to be warmed up promptly.
If your home regularly dips below 60°F at night, layering a warmer sleep sack (up to 3.5 TOG) with a cotton bodysuit underneath is one option. But for most homes where the thermostat is set anywhere in the 65°F to 70°F range, the nursery will stay well within safe limits for a properly dressed baby.