2.5 TOG Sleep Sack: Room Temperature and What to Wear

A 2.5 TOG sleep sack in the Baby Layers app: for a room of 12–20°C. What goes under it, by age, and how it compares with the makers' charts.

A 2.5 TOG sack is the everyday sack for a room inside the range the safe-sleep charities recommend, and the warmest the app ever suggests. It comes up for a room of 12–20°C.

18–20°C: long-sleeve bodysuit. Under 18°C: long-sleeve bodysuit and sleepsuit.

The sack makers' charts give 2.5 TOG for a room of 16–20°C. The safe-sleep charities point to those charts, and your sack's own label wins over any table.

Baby Layers uses it for 12–20°C, as its own table below shows.

0–3 months: Under 21°C. 3–6 months: Under 21°C. 6–12 months: Under 21°C. 1–3 years: Under 20°C.

Warmer than 20°C: a 1.0 TOG sack over short-sleeve bodysuit.

Below 12°C the app's range for sleep ends.

Never a hat for sleep — a baby cools through the head.

A sleep sack, never a loose blanket.

Safer slightly cool than too warm: nothing makes the sack warmer than the chart.

No hot-water bottle or electric blanket, and not next to a radiator or heater.

Check the neck — warm but not sweaty means just right.

Sources

What temperature is a 2.5 TOG sleep sack for?

In the Baby Layers app, a room of 12–20°C. The makers' charts give 2.5 TOG for 16–20°C.

What should a baby wear under a 2.5 TOG sleep sack?

18–20°C: long-sleeve bodysuit. Under 18°C: long-sleeve bodysuit and sleepsuit. Nothing goes on top of the sack: it is the whole of the bedding.

Is a 2.5 TOG sack all right for a newborn?

The chart is the same from birth to a year, and the app never dresses a newborn warmer than it for sleep. A swaddled newborn wears the swaddle in the sack's place, until the first signs of rolling.