Safe Sleep Layering by Room Temperature (°C) — For 0–3 months

Overheating raises the risk of sleep-related problems, so the goal is simple: keep baby comfortably warm, not hot. Many experts suggest a sleep-space around 16–20 °C, with light bedding or a well-fitting sleep bag. Use a room thermometer and adjust layers as the temperature changes. The Lullaby Trust+1

That said, there’s no single “perfect” temperature—what matters most is dressing appropriately for the room and checking baby (not the cot) for warmth. Red Nose Australia

How to layer (starting points)

Use this as a guide and adjust for your baby. “TOG” = warmness rating of sleepwear; brands vary, so always check the maker’s chart. ergopouch.com+1

• 16–18 °C → Long-sleeve cotton bodysuit + footed sleepsuit + 2.0–2.5 TOG sleep bag.
• 19–20 °C → Long-sleeve bodysuit + 2.0–2.5 TOG sleep bag.
• 21–22 °C → Short- or long-sleeve bodysuit + 1.0–1.5 TOG sleep bag.
• 23–24 °C → Short-sleeve bodysuit + ~1.0 TOG sleep bag.
• 25–26 °C → Sleeveless/short-sleeve bodysuit + 0.2–0.5 TOG sleep bag.
• ≥27 °C → Very light: breathable bodysuit or ultra-light (0.2–0.5 TOG) sleep bag; monitor closely. Love to Dream US+1

Quick safety checks (every nap & night)

• Feel baby’s chest/torso: Warm and dry = good. Hot, sweaty, flushed, or fast breathing = too warm; remove a layer. Hands/feet can feel cool and still be fine. HealthyChildren.org
• No hats indoors, no loose blankets, and keep the cot clear (use a well-fitting sleep bag or tightly tucked light bedding). HealthyChildren.org+1
• Back to sleep, on a firm, flat surface; room-share (not bed-share) for the first months. AAP Publications

Why we like sleep bags

A properly sized sleep bag keeps faces uncovered and reduces the need for loose blankets. Fit matters—especially around the neck and arm openings—so baby can’t slip down inside. The Lullaby Trust

Remember: these are starting points. Every baby runs a little warmer or cooler. Keep the room in the 16–20 °C range when possible, check baby’s chest, and adjust layers as needed. If you’re unsure—or if baby was premature or has health concerns—ask your health professional.