I agree with Kellie, Rebecca. The microwave kills all the antibodies etc in the milk. It also heats unevenly so it is not the best way of heating any drink for babies (due to the risk of burns). If the day care centre says that can only heat in a microwave they are being lazy. At our centre they heat it in warm water (which is the recommended way to do it), but they have to wear gloves to do it and then a different set of gloves to serve it (WH&S regulations apparently). The kitchen has to be off-limits to kids with a child proof door or gate by law also so it is certainly not a risk to a child. I would say the staff just can't be bothered at your centre. I would be really concerned about a centre that is not prepared to heat milk properly.