How to Dress Baby for Sleep: TOG and Room Temperature Charts

Start with the room, not the outfit

Every dressing decision is downstream of one number, and it is not on the clothing label — it is the temperature where she actually sleeps. Not the hallway, not the thermostat reading from a unit mounted by the front door in a differently-heated part of the house. The corner of the room where the crib sits, at the height the crib sits.

The AAP does not publish a single mandatory degree figure. What its safe-sleep guidance does say is to keep the room at a temperature that is comfortable for a lightly clothed adult, and to avoid overheating. Practically, most parents land somewhere in the high 60s to low 70s Fahrenheit, and the reason there is no exact number is that a room is not one temperature — a crib under a window in January and a crib against an interior wall are two different environments in the same house.

So the first purchase worth making is not sleepwear. It is a cheap thermometer that sits at crib height and reports the room she is in. Check it once at bedtime and once during a night waking for a week; you will learn your house's real overnight curve, which in most homes drops meaningfully after the heating cycles down. Once you know that number, the rest of this page is a lookup.

TOG, translated into English

TOG stands for thermal overall grade. It is a textile industry measure of thermal insulation, not a medical or regulatory standard, and no health authority assigns it. It exists because sleep sack manufacturers needed a way to say *how warm is this thing* on a tag, and it is the single most useful number on infant sleepwear once you know how to read it.

Higher TOG means more insulation. The scale sleepwear uses is narrow and roughly maps like this: 0.2 is barely more than a bedsheet, 1.0 is a light layer, 2.5 is a duvet-equivalent, and 3.5 is for a genuinely cold room. Because it measures the garment and not the whole outfit, the layer worn underneath still counts — a 1.0 sack over a short-sleeve bodysuit and the same sack over a footed cotton pyjama are two different total warmths.

Two caveats that matter. First, TOG is not tightly standardized between brands, so a 1.0 from one company and a 1.0 from another can differ; the manufacturer's own chart for the specific sack you own beats any general chart, including mine. Second, TOG says nothing about safety — only warmth. A high-TOG sack is not safer or less safe than a low one. It is warmer.

The chart I wish someone had handed me

Read this as a starting point, then adjust to your own baby over a few nights. It assumes a sleep sack rather than loose bedding, because loose bedding is not recommended in the sleep space during the first year. Every combination below is one base layer plus the sack.

The reason the same room temperature can produce two different rows is that babies are not identical and neither are houses — a drafty older bedroom at 68°F does not feel like a well-sealed one at 68°F. Start in the middle of the range and adjust based on how she feels at the chest, not on how she feels at the hands.

Counting layers when you have no chart at all

Traveling, staying with family, or holding a sack whose tag has been washed into illegibility — this is when the AAP's one-sentence version earns its keep. Their guidance: “Your baby only needs one more layer than you would wear in the same environment to be comfortable.”

To use it, be honest about what *you* would wear in that room at that hour, asleep and still, not what you are wearing right now while moving around the house. If you would sleep under a sheet in a t-shirt, she is in a bodysuit plus a light sack. If you would want a duvet and long sleeves, she is in a footed pyjama plus a warm sack. A diaper counts as nothing. A bodysuit is one. A footed pyjama is one. A sleep sack is one. Add them.

The layer count is also what makes travel manageable, because it survives a change of climate. You are not memorizing a chart; you are running one comparison against yourself in whatever room you have ended up in, which works in a hotel, a grandparent's spare room, or a house whose heating you do not control.

Why the sack replaced the blanket

The reason infant sleepwear got this specific is that the obvious solution was removed. Loose bedding is not recommended in an infant sleep space: the AAP lists pillows, quilts, comforters, mattress toppers, non-fitted sheets, blankets, toys and bumper pads together as things that increase the risk of entrapment, suffocation and strangulation. NICHD makes the same point about sleeping under quilts, blankets and other soft coverings.

Which leaves a real problem. Cribs are not warm places, houses cool overnight, and a baby who kicks has no way to recover a covering she has kicked off. A wearable blanket answers that by putting the warmth on the baby rather than over her — it cannot be kicked off, cannot ride up, and does not need to be tucked.

This is the one product category where I am speaking from actually using the thing rather than reading about it. A sleep sack was what I used with my daughter, and the reason was not that it was clever; it was that it made the safe-sleep instruction livable. I did not have to choose between a bare crib and a warm baby. If you want the fuller picture of what does and does not belong in the crib, and when a real blanket becomes appropriate, that has its own page, and the homepage maps how all of this fits into the first-year timeline.

Check the chest. Ignore the hands.

Cold hands are the single most common reason parents add a layer they should not. Infant extremities run cool as a matter of normal circulation, so hands and feet are simply a bad thermometer. Feel the back of the neck or the centre of the chest instead: warm and dry is right, sweaty is too warm, genuinely cool across the torso means add a layer.

The AAP lists specific overheating signs worth knowing by heart, because they show up in the swaddling guidance in the same breath as the warning that swaddling can increase the chance a baby overheats: sweating, damp hair, flushed cheeks, heat rash, and rapid breathing.

If you find her sweaty, take a layer off rather than opening a window — you can control clothing precisely and drafts you cannot. And when in doubt between two options, the guidance's general posture is that overheating is the risk being actively warned about, which is a useful tiebreaker at 1am when you are standing over the crib holding two sleep sacks.

• Sweating or damp hair at the back of the neck
• Flushed cheeks
• Heat rash
• Breathing that seems rapid
• Skin that feels hot rather than pleasantly warm at the chest

Swaddle, transition, arms out: dressing changes with the calendar

What you put on her is not fixed for the first year, and the change is triggered by a skill rather than a birthday. The AAP is direct: “Stop swaddling as soon as your baby shows any signs of trying to roll over. Some babies start working on rolling as early as 2 months of age.” Signs of *trying* — rocking onto a hip, twisting during a change — not a completed roll.

After that, the guidance distinguishes between two things that both get called sleep sacks. Wearable blankets that compress the arms, chest and body should stop once rolling starts. Sacks that do not swaddle and let her move freely can, per the AAP, be used as long as you want.

So the arc for most families is: swaddle in the newborn weeks, a transition product or an arms-out sack the moment rolling attempts appear, then a plain arms-out sack for as long as it still fits. Sizing matters more than it looks — the neck opening should be small enough that the sack cannot ride up over her face, and the body roomy enough for hips and legs to move.

Hot weather, and the newborn who is dressed for a different season

Summer is where the one-extra-layer rule gets misapplied most, because parents add the layer to an outfit that was already too warm. In a genuinely hot room, one more layer than a lightly-clothed adult can mean a diaper and a 0.2 TOG sack, and nothing else. That looks alarmingly bare if you have been handed a drawer of fleece as a baby gift. It is not.

Newborns get dressed too warmly more often than older babies, for two reasons: they feel fragile, and hospitals and relatives both default to bundling. The overheating signs in the previous section apply from day one, and the AAP's swaddling guidance specifically flags overheating as a swaddle-associated risk — which is worth remembering in July.

Air conditioning changes the calculation but does not remove it. A room held at 70°F all night is easier to dress for than one that starts at 76°F and falls to 66°F by 4am, which is the actual pattern in a lot of homes running AC on a timer. If yours does that, dress for the coldest part of the night and accept a slightly warm first hour, rather than the reverse. Fans should point at the room rather than at the crib.

Things not to put on her

A short list, and the reasoning behind each, because these come up constantly in gift piles and secondhand advice.

Hats indoors. Head covering is a normal part of the first hours after birth in a hospital setting, but hats for indoor sleep are a different thing — an infant sheds heat from her head, and covering it during sleep both raises the overheating risk and introduces something that can slip over the face.

Hoods, ties, and anything with cords. Drawstrings around a neck opening and long ribbon ties are not something you want in a sleep space where you are not watching.

Weighted sleepwear. Weighted sacks and swaddles have been marketed heavily and are not something I would put on a baby based on a product page; this is a direct pediatrician question, not a chart question.

Loose blankets, quilts, and any of the soft items on the AAP's list, for the whole first year. Also anything that props, tilts or wedges her — inclined sleepers and crib bumpers are banned in the US, which is a fairly loud signal about that whole category.

And one that is not a safety item but ruins nights anyway: scratchy tags, stiff seams, and anything with a chunky zip pull at the chin. You will find out at 2am.

• Hats or head coverings for indoor sleep
• Hoods, drawstrings, or long ties near the neck
• Weighted sacks or weighted swaddles without your pediatrician's input
• Loose blankets, quilts and comforters before 12 months
• Positioners, wedges, and inclined sleep surfaces of any kind