Hun I would be guessing the tog is at least 2. I have some bonds sugglesuit bags (no tog rating on them) and the winter one that I have been using up until about 2 weeks ago was really thick with the polyester filling. I used to bake DS is it! I was using lots of clothes underneath . So if you're going to use the bag just dress DD lightly (ie long sleeve romper without the legs and when it gets warmer try a short sleeve romper without the legs). I've recently bought a couple of the original grobags as they have a TOG rating and I know exactly what DS should be wearing under it. GL hun!