My DS is 12 months and I read somewhere that I should be transitioning him off the bottle for milk. I've been looking at sippy cups at the shops and many of them say they are not to be used for hot drinks, they should not be heated etc etc. What do people use for milk then? DS is still on formula but I will be transitioning him to cow's milk soon also. I was hoping to continue to use my bottle warmer with the sippy cup so it would be good to find one that fits in the bottle warmer and is safe to heat. Unfortunately he doesn't like his milk cold.