When I flew internationally last year I took an empty bottle for my 2yo and filled it up with milk from the coffee machine. By the time we boarded and ready for take off it had cooled enough for her to drink it while making the climb and keeping her ears popped.
As I said in the parent thread, what a great idea.
When I last flew with my sister and her then 2 y.o. son she had a drinking-bottle of milk, the sort with the flip up drinking tube. When we reached cruising altitude she gave it to him, and as he flipped open the top there was quite the stream of liquid into his face due to the pressure difference. Funniest thing on a plane - ever. We still laugh about it.
So my tip is to use a screw cap lid style bottle, unless your child has a good sense of humour!
