Breast milk should not be heated up in the microwave. They should have a bottle warmer or you can sit the bottle in a container of hot water until it's warm (about 15 seconds). Warming it in the microwave destroys the nutrients within the milk. Here's some info:
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I would speak to the director or room leader about this and have a look at the centres policy in regards to breast milk. I've never worked in a centre where breast milk is heated in the microwave. It's usually not brought in frozen unless you have a freezer for storage.
As for formula bottles, they can be brought in a few ways it just depends on your centres facilities and policies. The way I really like is the families bring in the bottles with the right amount of cooled boiled water already in the bottle and the formula in a formula dispenser. So everything is already to go and pre-measured, you just heat up the water in the microwave (about 30 secs) then add in the formula, shake the bottle and then check its not too hot.
Some places will prefer to boil the water for bottles and have parents bring in a formula tin and you then measure out the amounts you will need (this will be stated on the tin and you need to pay close attention as different formulas all have different measurements and water:formula ratios. Also the amounts are different for different ages.
The best thing is for everything to be labeled clearly.
Also babies who are onto cows milk usually bring in their own milk from home unless it is supplied by your centre and stored it in the fridge and it can be heated in the microwave for about 30secs, just before use. You shouldn't heat it and then
Whoever you work with in the room should show you what you're meant to do but if they don't, don't be scared to ask as many questions as you need
