What Temperature Should Baby's Room Be? The 68-72°F Guide

Room temperature matters for one serious reason and one everyday one. The serious reason: overheating is a recognized risk factor for SIDS (sudden infant death syndrome). The everyday reason: a baby who is too warm or too cold sleeps worse, wakes more, and settles harder. Get the temperature right and you help on both fronts at once.

Babies are not small adults when it comes to temperature. They have a higher surface-area-to-body-mass ratio than you do, so they gain and lose heat faster, and their ability to regulate their own temperature is still developing. A room that feels perfectly comfortable to you under a comforter can be too warm for a baby in a sleep sack.

We're a UK-based team, so we'll be upfront that this guide is written for a US context: temperatures in Fahrenheit, US products and terms, and the framework that American families actually work within. Where a specific number depends on guidance we can't state precisely, we'll say so plainly rather than invent a figure. For the sleep-surface side of the picture, our US crib safety standards guide is the companion to this one.

Here is the honest version, because it matters: the American Academy of Pediatrics (AAP) does not publish a single exact "correct" nursery temperature. The AAP's safe sleep guidance is clear that babies should be kept from overheating, and it advises against overbundling, but it stops short of naming one magic number. Anyone who tells you the AAP mandates an exact degree is overstating it.

What you'll see recommended over and over by pediatricians, hospitals, and baby-sleep sources is a range that's comfortable for a lightly clothed adult — commonly cited as around 68 to 72°F. That's a sensible, widely used target. The point is not the exact digit; it's the principle underneath it:

• If the room feels comfortable for you in light clothing, it's usually about right for your baby dressed in a sleep sack and a light layer.
• When in doubt, cooler is safer than warmer, because overheating carries the real risk while a slightly cool baby just needs one more layer.
• Aim to keep it steady. Big swings — a room that's cold at bedtime and hot by 2 a.m. because the heat kicks on — cause wakings.

The single most useful thing you can buy is an inexpensive room thermometer, placed near where your baby sleeps rather than across the room or next to a vent. Don't rely on how the room feels to you when you walk in — your temperature regulation is completely different from your baby's, and guesswork is exactly what overbundling comes from.

Most American families now use a wearable blanket or sleep sack instead of any loose blanket in the crib — which is exactly right, since the crib should stay bare. Sleep sacks are rated by TOG (Thermal Overall Grade), a measure of how much warmth the fabric holds. Higher TOG means warmer. The whole job is matching the TOG, plus what's worn underneath, to the room temperature.

A widely used rule of thumb, roughly translated to Fahrenheit:

Room temperature	Sleep sack TOG	What to wear underneath
Above ~75°F (warm / heatwave)	0.5 TOG or no sack	Short-sleeve bodysuit, or just a diaper and light vest
~69-74°F	1.0 TOG	Short- or long-sleeve bodysuit
~61-68°F	2.5 TOG	Long-sleeve bodysuit, or footed pajamas
Below ~61°F (cold room)	3.5 TOG	Footed pajamas over a long-sleeve bodysuit

Treat this as a starting point, not a law — brands vary slightly and so do babies, so check your specific sleep sack's own chart and adjust based on how your baby feels (more on checking that below). Two rules that don't bend:

• Never add a loose blanket on top of a sleep sack. If your baby seems cold, move up a TOG or add a layer of clothing underneath — never a blanket in the crib.
• Skip the hat indoors. Babies release excess heat through their heads, and a covered head during sleep raises the overheating risk. Hats belong outdoors, not in the crib.

Get the sack fit right too: the neck opening should be snug enough that your baby can't wriggle down inside it, and the armholes shouldn't be so loose that the sack rides up over the face. If you're moving your baby out of a swaddle and into a sack, our guide on when to stop swaddling walks through that transition.

This is the anxiety that keeps parents standing over the crib at midnight, and the good news is there's a reliable method — and a common mistake to avoid.

The right check: feel the back of your baby's neck, or their chest and tummy. These core areas tell you the truth about whether your baby is too warm, too cool, or just right. The skin there should feel warm but not hot or sweaty.

The common mistake: judging by hands and feet. A baby's extremities are normally cooler because their circulation is still immature — cold hands do not mean your baby is cold. Piling on layers because the hands feel chilly is one of the most common routes to overheating.

Signs your baby is too warm:

• Hot or sweaty neck, chest, or back — the clearest signal
• Damp hair, especially at the back of the head
• Flushed, red cheeks (context matters — this can also be teething)
• Rapid breathing — worth attention, as it can signal overheating or illness
• Restless, unsettled sleep
• Heat rash — small red bumps, often on the neck and chest

Signs your baby may be too cool:

• A cool chest or tummy (not just cool hands and feet)
• Mottled or pale skin

If you feel a hot, damp neck, take a layer off or drop to a lighter TOG. If the core feels genuinely cool, add a layer. And the guiding principle again: if you're unsure, err slightly cool — you can always add warmth, but overheating is the risk you want to design out.

Most US homes have air conditioning, which is a real advantage — but AC brings its own quirks for a nursery. A few practical points:

• Don't aim a vent or AC airflow directly at the crib. A steady cold draft on your sleeping baby isn't comfortable or ideal. Position the crib away from vents, and let the room cool as a whole rather than blasting one spot.
• Watch the overnight swing. If your thermostat lets the temperature drift up while everyone sleeps, the nursery can climb into overheating territory by the early hours. A steady set point beats a big overnight rise.
• A fan can help air circulate in a warm room — point it at a wall or across the room, not directly at your baby. Some research has suggested fan use may be associated with reduced SIDS risk in warmer rooms, though air circulation matters more than blowing air straight at the crib.

When the AC can't keep up — or you don't have it — heatwave rooms need a different playbook:

• Close blinds and curtains during the day to keep the sun's heat out, especially on south- and west-facing windows.
• Strip layers right down: at the warmest, a diaper with a thin cotton bodysuit and no sleep sack at all can be appropriate. Cotton breathes; fleece traps heat.
• Open windows in the evening once the outside air is cooler than the room, and create cross-flow where you safely can (keeping cords and blind pulls well out of reach of the crib).
• Check your baby more often on very hot nights, and offer extra feeds — babies can need more fluid in the heat.

Never place the crib next to a radiator, heater, or in direct sunlight, and never use a hot water bottle or electric blanket for a baby. Those are direct heat sources that can cause rapid overheating. Our baby sleep in hot weather guide goes deeper on managing genuinely hot nights.

Temperature is one piece of a bigger safe-sleep picture, and it's one of the most preventable risk factors — which is why it's worth getting right. The AAP's core safe-sleep practices are the foundation everything else sits on:

• Back to sleep, every sleep — for naps and nights, until your baby can roll both ways on their own.
• A bare crib — firm, flat mattress with a fitted sheet and nothing else: no loose blankets, pillows, bumpers, or stuffed toys.
• Room sharing without bed sharing — baby in their own crib or bassinet, ideally in your room, for at least the first several months.
• A smoke-free environment.
• Appropriate room temperature and clothing — the piece this guide is about.

A few temperature-adjacent points that connect to the rest of safe sleep:

• No hats indoors during sleep — covering the head raises overheating risk.
• Remove outdoor layers when you come inside, even if your baby is asleep — wake them to take off a coat or snowsuit rather than let them overheat.
• Weighted sleep sacks, swaddles, and blankets are not recommended for babies. Warmth should come from an appropriately rated ordinary sleep sack, never a weighted one. We cover this in detail in our guide on whether weighted sleep sacks are safe.
• Fleece sleepwear plus a warm sleep sack can stack up too much heat. Cotton layers are usually the safer choice.

None of this is complicated once it's a habit: thermometer near the crib, feel the back of the neck, match the sack to the room, and lean slightly cool when unsure. For the full picture — safe setup plus gentle, workable sleep habits — laid out as a calm plan, our online sleep course brings it together.

Finally, this is sleep support, not medical advice. If your baby seems unwell, runs a persistent fever, or is unusually lethargic, talk to your pediatrician — and for any emergency, call 911.