How to use this chart
- Measure the room your baby actually sleeps in with a thermometer.
- Read across to find the recommended layers and TOG.
- Always check your baby's chest or back of the neck — not hands or feet.
- Adjust one layer at a time; don't add blankets on top of a sleep sack.
| Room temperature | Recommendation |
|---|---|
| Under 14°C | Long Sleeve Vest + Sleepsuit + 3.5 TOG sleep sack |
| 14–16°C | Long Sleeve Vest + Sleepsuit + 2.5 TOG sleep sack |
| 16–20°C | Long Sleeve Vest + Sleepsuit + 2.5 TOG sleep sack |
| 20–22°C | Short Sleeve Vest + Sleepsuit + 1.5 TOG sleep sack |
| 22–24°C | Short Sleeve Vest + 1 TOG sleep sack |
| 24–27°C | Nappy/Diaper or Short Sleeve Vest + 0.5 TOG sleep sack |
| Above 27°C | Just a Nappy/Diaper or Short Sleeve Vest (no sleep sack) |
How this chart was built
Every safer sleep organisation publishes slightly different wording, and every sleep sack manufacturer publishes its own recommendations. This chart takes the middle ground: the temperature bands and TOG pairings that appear consistently across The Lullaby Trust, NHS, NCT, Red Nose Australia and the big sleep sack brands, including Ergobaby, Love To Dream, HALO, Kyte Baby, Woolino, Slumbersac, Molis&co and Tommee Tippee.
Understanding TOG at a glance
- 0.2–0.5 TOG — hot rooms above 24°C (75°F)
- 1.0 TOG — warm rooms around 20–24°C (68–75°F)
- 2.5 TOG — cool rooms around 16–20°C (61–68°F)
- 3.5 TOG — cold rooms below 16°C (61°F)
Quick rule of thumb
One thin layer under a suitable TOG sleep sack covers most babies through the year. Add a layer underneath for cold rooms; drop the sleep sack entirely above 27°C.
A word on age and individual variation
These recommendations are a starting point, not a prescription. Newborns and premature babies may feel the cold more than older babies, and heavier, more active toddlers often run warmer. Always use the chest-check rule and adjust one layer at a time. If in doubt, your health visitor, midwife or GP can advise on your specific baby.
Based on guidance from The Lullaby Trust, NHS, NCT, Red Nose Australia, and major sleep sack manufacturers including Ergobaby, Love To Dream, HALO, Kyte Baby, Woolino, Slumbersac, Molis&co and Tommee Tippee.