Hello S.,
I see some of my friends who do use the microwave to heat up a bottle, but I do not recommend it. Everymorning, I heat up my twins milk on the stove, the old fashioned way. First, I pour milk into each sippy cup, then pour the milk in a sauce pan on the stove, get the milk just warm enough so the chill is gone. This is a much safer way for babies, IMO, to drink milk. And if you have a mini oven for your counter, if you ever decide to get those Gerber Graduates meals, just place the contents of that container on the broil pan and cook the food inside the mini oven. As you can see, I am not a big fan of the microwave. Honestly, how can microwaving any food be good for us. I am just realizing this now after using it since I was in high school in the 1980's.
If you have time, research, on the internet, the dangers of the microwave.
The way the micro wave breaks down the milk and the plastic it can not be good for your little ones body and mind.
God Bless,
M.