How to Read a Tog Rating

A tog rating is a measurement of warmth, used most often on duvets but also seen on some brands of baby sleeping bag. It effectively measures the temperature difference between two surfaces of material, assuming heat as a constant, to create an accurate gauge of the warmth added by the material itself. This way, consumers can guesstimate the warmth of the bedding they're considering for purchase.

While the range of tog ratings for a duvet is generally 4 (for a lightweight spring duvet) to 14 (for a thick winter duvet), ratings on your average baby sleeping bag run lower.

You can find a baby sleeping bag with a tog rating of 0.5 to 3. The ratings on these are lower with good reason: infant pyjamas are typically made to be warmer than standard adult pyjamas, and can be worn beneath the baby sleeping bag. While an adult can escape the warmth of an overbearing duvet, an infant can't escape a baby sleeping bag, and the dangers of overheating are very real. Thinking conservatively can help consumers find a baby sleeping bag that's adaptable for all seasons.

Tog Ratings for Children and Adults

In fact, most children's bedclothes are rated lower than the comparable product for an adult. Some children have a naturally elevated temperature, and would feel smothered under a blanket an adult might consider comfortable. Infants, especially, must be carefully monitored to keep their temperatures in a safe range.

The use of a baby sleeping bag helps to regulate an infant's temperature, and if the tog rating is very low, can be safely used during spring and early summer. Although a baby sleeping bag might be more practical during the winter months, one with a moderate tog rating can be adjusted for use all year long.

Knowing the Rating You Want

If you already know the duvet or baby sleeping bag you plan to purchase includes a tog rating, it might be a good idea to check on the temperatures inside your home. If the main area of your house is frequently chilly but the room you have planned for a nursery seems to get all the heat, this is something you should be aware of before you buy a baby sleeping bag.

When you're buying for yourself, though, you don't need to be too worried. If the duvet is too warm, it can be removed, and if it's too cold, you can always add blankets. Some manufacturers sell a duvet set in two different tog ratings so that, separate or combined, they can be used all year long. Likewise, you should purchase more than one baby sleeping bag, as they're bound to become a mess at some point and will need to go into the wash. It's best to have several back-ups just in case.