What should my baby wear under their sleeping bag?
Make sure that baby is not over dressed under the sleeping bag. What your baby wears will depend on the TOG rating of the sleeping bag and the temperature of your baby’s bedroom. (In the same way as you would adjust nightclothes and number of blankets).
As a guide, please refer to the table below. Please remember, though, that babies are all different and, just as with blankets and sheets, you will soon discover what your baby is most comfortable wearing. To check a baby’s temperature, it is typically best to feel the tummy, chest and or back of their neck with your hand or use a thermometer if you choose. Babies hands and feet often feel cool, this is normal.
General recommendations are typically; Use only nappy and singlet in warmer weather and add a lightweight grow suit in cooler weather as a guide, however, Red Nose recommend that rather than state how many bedclothes can be safely placed on a baby (whether the baby is under blankets or in a sleeping bag), parents can work out the amount of bedding to be used after considering these following factors:
1. The room temperature where baby is sleeping.
2. How hot does the baby feel? A good way to check baby’s temperature is to feel baby’s back or tummy (don’t worry if baby’s hands/feet feel cool - this is normal).
3. Whether the baby has a cold or infection or another special need.
4. Consider how many layers that you as the baby’s carer are wearing comfortably.
IMPORTANT NOTE: The below chart is simply a rough guide and the above mentioned should be considered before deciding what items to wear on your baby under a sleeping bag or blankets if you are not using a sleeping bag. 
