What Should Newborn Wear To Sleep

Figuring out what should newborn wear to sleep is one of the most common and important questions for new parents. Getting it right helps your baby sleep safely and comfortably, giving you both more rest.

Dressing a newborn for sleep isn’t just about warmth. It’s a key part of safe sleep. The goal is to keep them cozy without overheating, which is a risk factor for SIDS. This guide will walk you through everything you need to know, from fabric choices to adjusting for room temperature.

This core principle is often called the “rule of thumb.” You should dress your baby in one more layer than you would wear to be comfortable in the same room. Since you’ll likely be in lightweight pajamas, your newborn will typically need that plus one.

For most homes, this means a simple, practical outfit. The safest and most recommended choice is a wearable blanket or sleep sack over a onesie or footed pajamas. This keeps them warm without the risks associated with loose blankets in the crib.

Understanding the TOG Rating System

You’ll often see sleep sacks labeled with a “TOG” rating. This measures thermal resistance. A higher TOG means warmer. Here’s a quick guide:

TOG 0.5: For very warm rooms (75°F and above). Lightweight muslin or cotton.
TOG 1.0: For standard room temperatures (68-72°F). This is the most common.
TOG 2.5: For cooler rooms (61-68°F). Made of thicker, quilted material.
TOG 3.5: For cold rooms (below 61°F). Usually reserved for poorly insulated spaces.

Step-by-Step: Dressing by Room Temperature

Use a reliable room thermometer. The baby’s room should be between 68°F and 72°F (20°C to 22.2°C) for ideal sleep. Here’s how to dress them:

For a Warm Room (74°F+)

A short-sleeve onesie or just a diaper is often enough.
Use a TOG 0.5 sleep sack if you want a light cover.
Always check for signs of overheating.

For an Ideal Room (68-72°F)

Start with a long-sleeve bodysuit or onesie.
Add footed pajamas made of cotton.
Place them in a TOG 1.0 wearable sleep sack.
This is the perfect, safe sleep outfit for most nights.

For a Cool Room (Below 68°F)

Begin with a long-sleeve bodysuit.
Use heavier footed pajamas.
Choose a TOG 2.5 sleep sack.
You might add socks under the footies for extra warmth.

Choosing the Right Fabrics and Materials

Natural, breathable fibers are best. They help regulate body temperature and reduce the risk of overheating.

100% Cotton: The gold standard. It’s soft, breathable, and easy to wash.
Muslin: A woven cotton that’s lightweight and gets softer with each wash. Great for summer.
Bamboo: Naturally temperature-regulating, moisture-wicking, and very soft. A good option for sensitive skin.
Lightweight Wool (Merino): Excellent for temperature regulation in various climates. Ensure it’s designed for babies and not to bulky.

Avoid polyester and other synthetics for base layers, as they can trap heat and moisture against the skin.

What NOT to Put on a Sleeping Newborn

Safety always comes first. Avoid these items in the crib:

Loose Blankets: They can cover the baby’s face and are a suffocation hazard.
Pillows, Cushions, or Soft Toys: These are not safe for sleep until after the first year.
Hats for Indoor Sleep: Hats can slip down and also cause overheating. Babies release excess heat from their heads.
Thick, Padded Clothing: Bulky coats or snowsuits can be to restrictive and lead to overheating.
Headbands or Bows: These can become a choking or strangulation hazard.

How to Check Your Baby’s Temperature

Don’t rely on feeling hands or feet—they’re often cool normally. Instead:

Place two fingers on the back of their neck or their upper chest.
If their skin feels warm and dry, they’re dressed perfectly.
If it feels clammy or sweaty, they are too hot. Remove a layer.
If it feels cool, they may be too cold. Add a layer.

A baby who is overheating may also have flushed cheeks, rapid breathing, or damp hair.

Special Considerations and Adjustments

Every baby and situation is unique. Keep these factors in mind:

For Preterm or Low-Birth-Weight Babies

These babies have less body fat and struggle more with temperature regulation. They often need an extra layer compared to a full-term baby in the same environment. Your pediatrician will give you specific guidance.

Swaddling as Sleepwear

Swaddling can be very effective for calming newborns. If you swaddle:

Use a thin, breathable muslin or cotton swaddle blanket, or a dedicated swaddle sack.
Stop swaddling as soon as your baby shows signs of trying to roll over, which can happen as early as 2 months.
Never place a swaddled baby in a sleep sack on top—it’s one or the other.

Diaper Changes and Nighttime Feeds

Choose sleepwear that makes nighttime changes easy. Look for:

Zipper pajamas that open from the bottom or top-to-bottom.
Sleep sacks with a two-way zipper.
Snaps can be fussy in the dark, but some parents prefer them.

Seasonal Sleepwear Guide

Summer Sleeping

In hot weather, the main goal is preventing overheating.

A short-sleeve onesie and a TOG 0.5 muslin sleep sack is often perfect.
In a heatwave, just a diaper may be appropriate.
Use a fan to circulate air (point it at a wall, not directly at the crib).
Close blinds during the day to keep the nursery cool.

Winter Sleeping

Focus on warm layers, not thick ones.

Start with a long-sleeve bodysuit.
Add fleece or heavier cotton footed pajamas.
Use a TOG 2.5 or 3.5 sleep sack for very cold rooms.
Remember, indoor heating can dry the air; a humidifier can help.

Creating a Safe Sleep Environment

Sleepwear is just one part of the safe sleep picture. Always follow the ABCs of safe sleep:

Alone: Baby should sleep alone in their own crib or bassinet.
Back: Always place them on their back for every sleep.
Crib: Use a firm, flat mattress with a fitted sheet in a safety-approved crib.

The room should be smoke-free. Consider offering a pacifier at nap and bedtime, once breastfeeding is established, as it’s linked to a reduced risk of SIDS.

FAQs: Your Newborn Sleepwear Questions Answered

Q: Can my newborn sleep in just a onesie?
A: Yes, in a warm enough room (above 75°F), a short-sleeve or long-sleeve onesie can be sufficient sleepwear. Always check for signs of being to cold.

Q: Are footie pajamas safe for sleep?
A: Absolutely. Footed pajamas are an excellent choice as long as they are fitted (not loose or baggy) and made of breathable fabric. Ensure they are the right size so the feet aren’t to tight.

Q: How many sleep sacks do I really need?
A: Having 2-3 is practical. This allows for one to be in the wash if there’s a diaper leak or spit-up. You may want different TOGs for different seasons.

Q: Should I put socks on my newborn under their pajamas?
A: If the pajamas have feet, socks aren’t necessary. If you’re using a non-footed onesie under a sleep sack, socks can help keep feet warm. Make sure they are snug but not tight.

Q: What if my baby always seems to break out of their swaddle?
A> This is very common. Consider switching to a swaddle sack with velcro or zipper closures, which are more secure than a traditional blanket swaddle. They also make the transition to a regular sleep sack easier later on.

Q: Is it okay to use a hand-me-down sleep sack?
A: It’s fine as long as it’s in good condition. Check for loose threads, broken zippers, or worn fabric. Ensure it still fits the current safety standards (no loose fabric around the neck).

Trusting Your Instincts

While guidelines are essential, you know your baby best. If they consistently wake up cold or sweaty, adjust their layers. The “one more layer than you” rule is a starting point, not a strict law. Pay attention to your baby’s cues and the specific conditions in your home.

Remember, the goal is safe, comfortable sleep for your little one—and more peace of mind for you. By choosing the right breathable layers and following safe sleep practices, you’re creating the best possible environment for your newborn to rest and grow. With a little practice, dressing them for sleep will become second nature.