Sleeping Bag Tog Guide, Choosing by Season

What Does Tog Actually Mean?

Tog is a measure of thermal insulation, originally used for duvets, and it works the same way for baby sleeping bags. The higher the tog rating, the warmer the sleeping bag, so choosing the right one comes down to matching tog to room temperature rather than the season alone, since a warm nursery in winter needs less insulation than a poorly heated room.

Tog Rating by Room Temperature

Choosing a Sleeping Bag for Your Baby's Needs

Tog is only half the picture, since fit and features matter for comfort too. For active babies who tend to kick off blankets, an Anti Kick Sleeping Bag, Removable Sleeves keeps them covered while allowing sleeves to come off as the room warms up through the night.

For younger babies still adjusting from swaddling, a Swaddle Blanket with Lace Edge offers a lighter, more flexible layer that can be used alongside or instead of a full sleeping bag in warmer conditions.

Signs Your Baby Is Too Warm or Too Cold

• Too warm: sweating, damp hair, red cheeks or a flushed chest
• Too cold: cool hands and feet are normal, but a cold chest or tummy suggests more warmth is needed
• Check the back of the neck or chest, rather than hands and feet, for the most reliable temperature check

Layering Underneath

What your baby wears underneath the sleeping bag also affects overall warmth. A short sleeve bodysuit under a mid tog bag usually suits average room temperatures, while a long sleeve bodysuit or babygrow adds extra warmth for a cooler room without needing to jump to a higher tog bag entirely.

Frequently Asked Questions

What tog sleeping bag should I use in a 20 degree room?
A 2.5 tog bag generally suits a room around 18 to 20 degrees, paired with a short sleeve bodysuit underneath.

Why does tog matter more than season alone?
Room temperature varies by home and heating, so a summer sleeping bag might still be right for a warm winter nursery, and vice versa.

Who needs a lower tog bag even in winter?
Babies in well heated rooms, or those prone to overheating, may still need a lower tog rating regardless of the season outside.

When should you switch from swaddling to a sleeping bag?
Most guidance suggests transitioning once a baby shows signs of rolling, usually between two and four months, for safety reasons.

How do you check if your baby is too hot at night?
Feel the back of the neck or chest rather than hands and feet, since these areas give a more accurate sense of overall body temperature.

Browse our baby sleeping bags, or read Do You Need a Baby Monitor? What to Consider for more on keeping an eye on your baby through the night.