Figuring out what should a newborn wear to sleep is one of the first and most important decisions you’ll make for your baby’s safety and comfort. Getting it right helps prevent overheating and supports safe sleep, giving you both better rest.
This guide will walk you through everything you need to know, from fabric choices to room temperature. We’ll cover simple rules and common mistakes so you can feel confident at bedtime.
What Should A Newborn Wear To Sleep
The core principle is to dress your newborn in one more layer than you would be comfortable wearing in the same room. Since babies can’t regulate their body temperature well, this simple rule is your best starting point. The goal is to keep them cozy without getting too hot.
Understanding the TOG Rating
You might see sleepwear labeled with a TOG rating. This measures thermal resistance. A higher TOG means warmer.
- 0.5 TOG: Very lightweight, for warm rooms above 75°F (24°C).
- 1.0 TOG: The most common, ideal for rooms between 68-72°F (20-22°C).
- 2.5 TOG: For cooler rooms, around 61-68°F (16-20°C).
- 3.5 TOG: Heavyweight, rarely needed for sleep unless the room is very cold.
The Role of Room Temperature
Your thermostat is your best tool. Aim for a room temperature between 68-72°F (20-22°C), which is considered ideal for infant sleep. Use a reliable room thermometer, not just your feeling, as drafts or humidity can change things.
How to Check Your Baby’s Temperature
Don’t rely on hands or feet, which are often cool. Instead, feel the back of their neck or their chest. It should feel warm and dry, not sweaty or clammy. A sweaty baby is too hot.
Step-by-Step Dressing for Sleep
- Start with a diaper. Use a clean, well-fitting diaper.
- Add a onesie or bodysuit. This is your base layer. Opt for soft, breathable cotton.
- Choose the sleep sack. This is the safest alternative to loose blankets. Select the TOG based on your room temp.
- Consider a hat? Almost always no. Babies release excess heat from their heads. A hat indoors can lead to overheating.
- Do a final check. Feel their chest or neck to ensure they are comfortably warm.
Essential Safe Sleep Clothing Rules
Clothing choices are a direct part of safe sleep practice. Following these rules reduces risks significantly.
- No Loose Items: Absolutely no blankets, quilts, pillows, or stuffed toys in the crib. These are suffocation hazards.
- Fitted is Best: All sleepwear should be snug-fitting but not tight. Avoid baggy pajamas.
- Skip the Strings: Avoid any clothing with ties, ribbons, or cords near the neck.
- Natural Fibers: Choose breathable materials like cotton, bamboo, or muslin over synthetic fabrics when possible.
Newborn Sleepwear by Season
Your baby’s sleep outfit will change with the weather. Here’s a seasonal breakdown.
Summer Sleep
In hot weather, a simple cotton onesie or a lightweight sleep sack (0.5 TOG) may be all thats needed. If using air conditioning, remember the one-more-layer rule based on the AC-cooled room temp, not the outdoor heat.
Winter Sleep
For cold rooms, a long-sleeved bodysuit under a fleece sleepsack (2.5 TOG) is often perfect. Resist the urge to add extra blankets. Instead, use a warmer sleep sack. Ensure the room isn’t too dry from heating; a humidifier can help.
Spring and Fall
These transitional seasons can be tricky with fluctuating temps. A standard 1.0 TOG sleep sack over a cotton onesie is a versatile choice. Be prepared to adjust the base layer if nights are cooler or warmer than expected.
Common Mistakes to Avoid
Even with the best intentions, it’s easy to make errors. Here are some frequent ones.
- Overbundling: This is the most common mistake. Overheating is a SIDS risk factor. More layers is not always better.
- Using a Blanket “Just in Case”: It only takes one time for a blanket to cover a baby’s face. It’s not worth the risk.
- Dressing in Heavy Clothes Under a Swaddle: A swaddle is a layer itself. A light onesie underneath is usually sufficient.
- Ignoring the Material: Scratchy tags, heavy embroidery, or non-breathable fabrics can disturb sleep and cause irritation.
Swaddling and What to Wear Underneath
Swaddling can soothe newborns by mimicking the womb. But what they wear under the swaddle is key.
Since the swaddle cloth or swaddle sack adds a layer, dress baby lightly underneath. A diaper and a short-sleeved onesie is often enough in a warm room. In a cooler room, a long-sleeved bodysuit may be better. Always ensure the swaddle is not too tight around the hips—their legs should be able to bend up and out.
Important: Stop swaddling as soon as your baby shows signs of trying to roll over, usually around 2 months. Transition to a wearable sleep sack at that point.
Choosing the Right Sleep Sack
A sleep sack (or wearable blanket) is the safest way to keep your baby warm. Look for these features:
- Appropriate TOG: Match it to your nursery’s usual temperature.
- Snug Neck and Armholes: It should not be able to ride up over the baby’s face.
- Room for Hips and Legs: It should allow for free leg movement for healthy hip development.
- Zipper or Snap Closure: Zippers with a tab cover at the top are safest. Some have bottom-up zippers for easy diaper changes.
Premature and Low Birth Weight Babies
Preemies often have even less body fat and more trouble regulating temperature. They may need an extra layer compared to a full-term baby. The hospital NICU will give you specific guidance. Often, they will recommend a preemie-sized sleep sack and possibly a hat initially, but always follow your pediatrician’s direct advice for your baby.
FAQs: Your Questions Answered
How do I know if my baby is too hot or too cold at night?
Check their chest or the back of their neck. Sweaty, damp, or very warm skin means they’re too hot. Cool skin (not just hands/feet) or a chest that feels cool means they’re too cold. Their behavior is also a clue—a too-cold baby may be restless or fussy, while an overheated baby may seem lethargic.
Can my newborn sleep in just a diaper?
In very hot weather, if the room is consistently above 75°F (24°C), a diaper alone might be appropriate. However, a lightweight, breathable cotton onesie or a 0.5 TOG swaddle can help wick moisture and is often better. Always prioritize a cool sleep environment over removing all clothing.
Are footed pajamas safe for sleep?
Yes, fitted footed pajamas (often called sleepers or sleep ‘n plays) are a safe and popular choice. Ensure they are the right size—not too tight on the feet and not so loose that fabric gathers near the face. Avoid ones with loose buttons or decorations that could detach.
What should a newborn wear to sleep in a 70-degree room?
This is the ideal temperature. A great option is a cotton onesie (short or long-sleeved) paired with a 1.0 TOG sleep sack. Alternatively, a fitted footed cotton pajama set on its own could also be suitable. Do a quick chest check after 20 minutes to confirm.
When should I stop using a sleep sack?
You can use a sleep sack as long as your baby fits in it and hasn’t started trying to climb out of the crib. Many toddlers use them into their second or even third year. They transition to a regular blanket when they are old enough to understand how to use one safely, usually well past the toddler years.
Is it okay to put a onesie under a swaddle?
Absolutely. In fact, it’s recommended. The swaddle is the outer layer. A simple short or long-sleeved onesie (depending on room temp) underneath provides comfort and a bit of extra warmth without the risk of overheating that a thicker garment might cause.
Final Checklist Before Bed
- Room thermometer reads between 68-72°F (20-22°C).
- Baby is dressed in a breathable base layer (like cotton).
- Sleep sack or swaddle is the correct TOG for the room.
- No hats, loose blankets, or soft bedding in the crib.
- Sleepwear is fitted, without strings or ties.
- You’ve checked their chest/neck for comfortable warmth.
- The crib mattress is firm with only a fitted sheet.
Remember, every baby is unique. You might need to try a few combinations to find what works best for your little one. Trust your instincts—if something seems off, adjust a layer. The fact that you’re researching what should a newborn wear to sleep shows you’re a caring and attentive parent. With these guidelines, you can create a safe and cozy sleep environment that helps your newborn—and you—get the rest you need.