Hi! I agree with starshine, bottles do not need to be warmed...all my kids have it at room temperature. Also, pre made formula has a limited shelf life, even in the fridge so having mom send it pre made won't work. If you are short on time, or lazy like me, make the parents bring nursery water so you don't have to boil/cool water!!! It's 97 cents at Walmart so no big deal and saves lots of prep time!