How to Dress Your Baby for Sleep and Weather (Without Overheating)

Key takeaways: Dress your baby in no more than one layer more than an adult would wear. Use a sleep sack instead of loose blankets. Keep the head uncovered for sleep. Feel the back of the neck or chest, not the hands, to check if your baby is too warm.

Parents often worry that their baby is cold. In fact, overheating is the more common problem, and it’s a known risk factor for SIDS. Here’s how to dress your baby comfortably and safely, day and night.

The Basic Rule

The AAP recommends dressing your baby in no more than one more layer than an adult would wear to be comfortable in the same environment. If you’re comfortable in a T-shirt, your baby might wear a onesie plus a light sleep sack.

How to Check Your Baby’s Temperature

Babies’ hands and feet often feel cool because of immature circulation. That doesn’t mean they’re cold. Instead, feel the back of the neck, chest, or belly.

• Just right: warm and dry.
• Too hot: sweaty, damp hair, flushed cheeks, heat rash, rapid breathing, or restlessness.
• Too cold: cool chest or belly, pale or mottled skin that doesn’t improve with warmth, or unusual fussiness.

Dressing for Sleep

• Use a wearable blanket (sleep sack) instead of loose blankets, quilts, or comforters. Loose bedding is a suffocation risk.
• Keep the head and face uncovered. Babies release heat through their heads. Hats are for outdoors and the first hours after birth in the hospital, not for sleep at home.
• Avoid weighted sleep sacks, swaddles, or blankets. They aren’t safe for infants.
• Choose breathable fabrics like cotton.
• Keep the room comfortable for a lightly clothed adult. Many experts suggest roughly 68 to 72°F (20 to 22°C), but the exact number matters less than how your baby feels.
• Don’t add heat sources like space heaters near the crib, or electric blankets.
• Fans: a fan can help circulate air in a warm room. Keep it out of reach and not blowing directly on your baby.

Using TOG Ratings

Many sleep sacks list a TOG (thermal overall grade) rating, which tells how warm the fabric is. Lower TOG is lighter. Manufacturer charts suggest which TOG and layers suit which room temperatures. These are helpful starting points, but always check your baby’s neck or chest.

Dressing for Hot Weather

• Dress your baby in a single light, loose layer, or just a diaper indoors on very hot days.
• Keep babies under 6 months out of direct sun; use shade, light long sleeves, and a wide-brimmed hat outdoors.
• Offer breast milk or formula more often. Babies under 6 months shouldn’t be given water.
• Never cover a stroller with a blanket to block sun; it traps heat. Use a breathable stroller shade.
• Never leave a baby in a car, even briefly.

Dressing for Cold Weather

• Dress your baby in layers you can add or remove: a onesie, a long-sleeve outfit, and a warm outer layer.
• Add a hat, mittens, and socks or booties outdoors.
• Use a stroller cover or carrier cover designed for cold weather, and bring a blanket for over (not under) the stroller straps.
• In the car seat, avoid bulky coats or snowsuits. They compress in a crash, leaving the harness too loose. Buckle your baby in thin layers, then put a coat or blanket over the harness.
• Remove extra layers when you go indoors, into a store, or into a warm car.

The Hospital Hat Question

In the hospital, newborns often wear hats in the first hours because they lose heat quickly right after birth. Once your baby is home and maintaining their temperature, they don’t need a hat indoors or for sleep.

Babies With a Cold or Fever

Don’t bundle a baby with a fever, which can raise their temperature further. For babies under 3 months, call the doctor for any rectal temperature of 100.4°F or higher.

Call your baby’s doctor if your baby: feels hot and seems lethargic, isn’t feeding well, has fewer wet diapers, or has a fever. Call 911 if your baby is unresponsive, has a seizure, or has trouble breathing.

The Bottom Line

Dress your baby like you, plus one light layer, and check the neck or chest rather than hands and feet. For sleep, use a sleep sack, keep the head uncovered, and keep the crib bare.

For more on safe sleep and everyday newborn care, see From First Breath to First Birthday.

Sources

1. Moon RY, Carlin RF, Hand I; Task Force on Sudden Infant Death Syndrome; Committee on Fetus and Newborn. Sleep-related infant deaths: updated 2022 recommendations for reducing infant deaths in the sleep environment. Pediatrics. 2022;150(1):e2022057990.
2. Moon RY, Carlin RF, Hand I; Task Force on Sudden Infant Death Syndrome; Committee on Fetus and Newborn. Evidence base for 2022 updated recommendations for a safe infant sleeping environment to reduce the risk of sleep-related infant deaths. Pediatrics. 2022;150(1):e2022057991.
3. Fleming PJ, Gilbert R, Azaz Y, et al. Interaction between bedding and sleeping position in the sudden infant death syndrome: a population based case-control study. BMJ. 1990;301(6743):85-89.
4. Durbin DR, Hoffman BD; Council on Injury, Violence, and Poison Prevention. Child passenger safety. Pediatrics. 2018;142(5):e20182460.
5. Council on Environmental Health and Section on Dermatology. Ultraviolet radiation: a hazard to children and adolescents. Pediatrics. 2011;127(3):588-597.
6. National Institute of Child Health and Human Development. Safe to Sleep campaign. https://safetosleep.nichd.nih.gov

This article is for general education and is not a substitute for individualized medical advice. Always talk with your baby’s health care provider or your own provider about your specific situation. If you think your baby or you may have a medical emergency, call 911.