I heat it in the microwave. I boil the water on the stove and pre make bottles and store them in the fridge but not for more than 24 hours. I've had no problems and the health centre hasn't a problem with it either.
Posted Sunday 14 March 11:02pm
I read recently (sorry can't remember where) that although heating formula in the microwave can kill some of the nutrients that it doesn't effect it that much and is therefore not a problem.
I heat my bub's bottles in the microwave. It's so quick and easy with a screaming baby at 2am.
Just make sure you shake it up well to get rid of any hot spots.