N.W.
Since you can't microwave breastmilk.....here is a trick i used with my daycare kids when we would go out for trips to the park, etc. and had no running hot water available to put it under.
I have a "man's" thermos, you know the kind they take their hot coffee to work in? Well i would boil water and fill that. Don't fill it all the way to the top so that you can fit a bottle inside of it when you need to heat it. Not all bottles will fit in it though, you might have to check that. i will tell you, it is SO much faster to heat it if you pump and store it in the bags vs. the bottles. In the bags it will heat in a fraction of the time, then you can pour it into the bottle for feeding, and the bag will fit into the thermos with no problems(which is how we did it). Your baby won't have to wait as long for a feeding this way.
Hope this helps!