Both mine love cows' milk but I try not to give it to them, since, well, let's just say the house stinks for the next 24 hours and you wouldn't want to light a match near my kids after they have cows' milk!
Josie is 7 and Nat is 4 and they're healthy and get lots of calcium. They DO eat yogurt, would eat it by the tubful if I let them - the culturing of yogurt means the milk sugars are partially digested and they can handle it without the nasty aftereffects. They eat more cheese than I'd like, but one cheese stick a day they can usually handle, or a couple slices in a sandwich. They'll occasionally eat broccoli, but J will eat lettuce with dressing so I know she's getting some there, and they'll both eat salmon, which is also rich in calcium. Nat will drink rice milk (fortified with calcium) no problem, although J won't touch the stuff, but J WILL drink kefir (a cultured milk beverage) and yogurt smoothies. Top off with a decent supplement and we're doing OK.
I have a friend whose DD is highly allergic to cows' milk and she's found some good supplements out there; you just have to do your research.
As for the temperature, I rad someplace that warm milk actually activates different taste buds than cold milk, so there's definitely some validity to that idea.
Anyway, if changing the temperature doesn't help, you can try working around it. There are other ways to get the calcium into them.
