Generally speaking Sara, babies get all of the fluid they need in the breastmilk (not absolutely sure about formula but you'd think it'd be the same) so they don't need water at this age....

That said, lately Maddy has had a cold so I figured that extra fluids (water only) can't hurt her (GP said it was fine) and the earlier she gets used to drinking water the better for her. You can tell she gets 'brain freeze' from the cold water....it's funny stuff.

I give her the chilled water in her bottle a few times a day, she'd be lucky if she had 5mls at a time but she likes to suck and chew on it. It doesn't effect the length of her feeds so I'm happy to give it to her.