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What is TOG?

TOG is an international standard for warmth and thermal effectiveness. A TOG is the unit measurement of thermal resistance and is used to estimate warmth.

TOG may be used as a general guide to help parents choose the appropriate level of warmth for their baby’s coverings for their environment.

TOG Chart


What to wear under the zzZipMe Sack. Usually a long sleeve or short sleeve bodysuit is worn under the ZMS. In colder environments long johns or pajamas may be worn under the ZMS. In warmer environments, a short sleeve bodysuit or just a diaper.

Each baby is unique and parents should touch and feel their baby’s neck or tummy to ensure baby is not too warm or too cold. If baby is sweaty a layer should be removed. If baby feels too cool, an additional layer may be added under the ZMS.