Becca I have the same problem with Daniel. Daniel's dad always has a fan on at night (even in Winter. I have to really snuggle down in to the blankets to keep warm.) Daniel has inherited this little trait. We went out with Daniel and his grandparents not long ago and my mum was freaking out because she though that Daniel was going to get too cold with what we had dressed him in.

I knew very well that he was not going to get cold as he is a warm baby and is much more likely to over heat. I've only just recently started giving him water - mostly because it was winter and I do tend to put more water in his AF then recommended. (More water is never going to hurt). At three weeks I don't know how your little one would go drinking water, or whether he even needs to. They seem to be able to tell that water has a different texture and don't seem to like drinking it as much.

I guess I don't really know the answer to the water question....... useful, aren't I?