Sleep

What temperature should the baby's room be?

The actual range

The AAP recommends a baby's sleep environment between 68-72°F (20-22°C). The narrower target most pediatric sleep specialists recommend is 68-70°F. The cooler end (68°F) is preferable to the warmer end (72°F) — overheating is a known and modifiable SIDS risk factor; being slightly cool is not a comparable risk for healthy term babies.

What this means in practice: most modern American homes are heated to 70-74°F as a default, which is at the warm edge or above the recommended range. If your house thermostat reads 72°F downstairs, the upstairs nursery is probably 73-75°F, which is too warm for sleep.

How to actually measure

Thermostats lie. They measure where they live (usually a hallway), not where the baby sleeps. The temperature in the crib is what matters.

The simplest accurate setup:

• A digital room thermometer placed in or beside the crib — not on the wall across the room
• A separate thermometer on the wall to gauge the room as a whole
• Check at the times that matter: bedtime (when baby goes down) and 3-4 a.m. (typically the coldest part of the night when the heat has cycled off, or warmest when the morning sun starts)

Why overheating matters

The SIDS link: babies don't thermoregulate as well as adults. They rely heavily on the head (which can lose 25%+ of body heat) and they can't move blankets off themselves to cool down. A baby who is too warm goes into deeper sleep and is less likely to wake from breathing irregularities — which is the leading hypothesis for the SIDS mechanism.

The AAP's 2022 safe sleep guidelines specifically call out overheating as a modifiable risk and recommend:

• Lightly dressed (one more layer than you'd be comfortable in)
• Room temperature at the cooler end of the comfortable adult range
• No hats indoors during sleep
• Avoid heavy bedding, sleep sacks rated above the room temperature, or layered swaddles in warm rooms

What to dress baby in

Clothing layers are the more practical lever than heating. Most American houses are within the 68-72°F range somewhere — the question is what to put the baby in.

A standard reference (TOG values — thermal overall grade):

• Room 75°F+ (too warm): Short-sleeve onesie only, or 0.5 TOG sleep sack over a short-sleeve onesie
• Room 70-74°F: Long-sleeve onesie + 1.0 TOG sleep sack, or footed pajamas alone
• Room 65-69°F: Long-sleeve onesie + 1.5 TOG sleep sack, or footed pajamas + 1.0 TOG sack
• Room 60-64°F: Long-sleeve onesie + 2.5 TOG sleep sack, or layered footed pajamas + 1.5 TOG sack
• Below 60°F: Address the room temperature; this is below recommended range

Seasonal adjustments

Summer: This is when overheating risk peaks. AC matters. If you don't have AC and you're in a hot climate:

• Fans help dramatically (the AAP specifically endorses fans as SIDS-protective in non-AC settings)
• Open the window crack at night for circulation
• Dress baby in nothing but a diaper or short-sleeve onesie
• Skip the swaddle; use a muslin sleep sack at most
• Use a thermometer; don't trust your perception of the room

• Don't put a space heater near the crib (fire and carbon monoxide risk)
• Crack the bedroom door so the heat isn't trapped
• Dress baby for the actual room temperature, not the perceived chill (most newly-cold winter rooms are still 68-70°F at floor level)

The couple impact

This section gets ignored in most sleep guides and matters more than people realize. If your normal preference is to sleep in a 65-67°F room and the baby's room is 70°F, somebody is uncomfortable. Couples we know have figured out:

• Slightly different temperature in the baby's room vs the adult bedroom (when they're separate rooms) — most thermostats can be set per zone
• For room-sharing setups, the parents adjust to the baby's room temperature and use lighter or heavier bedding for themselves to compensate
• A small fan in the parental sleep area to direct cool air at the adults without affecting the baby's sleep area
• Heated mattress pads on the parental side of the bed (for cold-preferring parents stuck in a 70°F room)

Edge cases

Baby keeps kicking off the sleep sack. Normal. If the room is in range, this isn't a problem; the sack covers the body even when wriggled. Wearable blankets are designed for this; loose blankets in the crib are not safe at any age before 12 months.

Baby seems to sleep better in a cold room. Common. Cool rooms support deeper sleep for many babies. As long as the baby is dressed for the temperature and feels warm at the chest, cooler-than-AAP-target is fine.

Baby wakes shivering or with cold cheeks. Underdressed. Add a layer at bedtime and recheck.

Baby wakes sweaty. Overdressed or room too warm. Remove a layer or lower the room temperature; this is the version of mistake to fix immediately.

What we'd buy

The two pieces of equipment most useful for this:

1. A digital crib-side thermometer ($10-20). Reads accurately, easy to glance at during night feeds. 2. A TOG-rated sleep sack ($30-50) — Halo, Kyte Baby, or Woolino are the three most-recommended brands. Sleep sacks specifically rated 1.0 TOG (for warm rooms) and 2.5 TOG (for cold rooms) cover most year-round needs in two pieces.

The seasonal swap is the only actually-useful clothing decision. Beyond that, room temperature in range and one good thermometer are most of the work.

Sources

• AAP 2022 Safe Sleep Guidelines
• AAP — Sleep Environment
• Mon AM et al. — Infant Thermoregulation Review

Related questions

• When do babies sleep through the night?
• When can a baby sleep with a blanket?

We cite the sources we relied on. This page is for general orientation only and does not replace medical advice from your pediatrician. If your baby has any specific feeding, sleep, or safety concern, always check with a clinician who knows your kid.