What your baby should wear at night depends largely on the temperature of the room, the season, and their age, but the key principles are safety, comfort, and breathability. Babies can’t regulate their body temperature as well as adults, so dressing them appropriately helps ensure they sleep soundly and reduces the risk of overheating—a known factor associated with sudden infant death syndrome (SIDS). A good rule of thumb is to dress your baby in one more layer than you would wear yourself to feel comfortable in the same environment. For example, in rooms between 20–22°C (68–72°F), which is the ideal sleeping temperature, most babies do well in a long-sleeve cotton onesie or pyjama and a light cotton sleep sack (also called a wearable blanket) with a TOG rating of around 1.0. If the room is cooler, you can opt for a slightly thicker sleep sack (2.5 TOG) and add a short-sleeve bodysuit underneath. Swaddles are suitable for newborns who aren’t rolling yet and can help them feel secure, but once they start rolling over (usually around 3–4 months), swaddling should stop immediately, and a sleep sack becomes a safer alternative.
In warmer conditions—say above 24°C (75°F)—lightweight clothing is best. A short-sleeve bodysuit or even just a diaper and a thin muslin swaddle may be enough. You should avoid hats, thick blankets, and overdressing, as babies release excess heat primarily through their heads and face. Always check your baby’s neck or chest (not hands or feet, which are often cooler) to see if they feel too warm or sweaty, which may indicate overheating. Hands and feet being a little cool is usually normal and not a sign that your baby is cold.
It’s also helpful to choose breathable, natural fabrics like cotton or bamboo, which wick away moisture and regulate temperature better than synthetic materials. Avoid loose blankets, duvets, pillows, or stuffed animals in the crib, as these pose suffocation risks. Instead, focus on fitted layers that are snug but not tight, and ensure the crib mattress is firm with a fitted sheet only.
In summary, dressing your baby for sleep means balancing warmth with breathability, adapting to the room temperature, and following safe sleep guidelines. When in doubt, check a baby sleepwear TOG guide, monitor your baby’s comfort regularly, and adjust layers as needed to keep them safe and sleeping well.
