I wrapped from birth to about 8 weeks, we found that because they don't tend to move a great deal you can keep them warm by wrapping with nice stretchy wraps and then tucking them in with layers over the top. I also found that by wrapping we stopped her waking herself up from the startle reflex which they lose from about 8 weeks. Some of the grobags for newborns are to be used from a certain weight only so be sure to check that too. We are in Melbourne and Izzy was born at the start of winter so it was a worry making sure she was warm enough! Remember too that bubbys will let you know if they are too cold, but overheating can be dangerous. Good luck!