I go back to work from my maternity leave the beginning of next month. My daughter will be close to a month and half old. Since i'm going back to work my father will be staying home most of the time to watch my daughter. I want to pre make bottles for him and put them in the fridge. When he warms one up and puts it in her little baby thermos for her.. about how long is the bottle good for until it has to be thrown out? Anybody know? He wants to have the bottle ready for her when she wakes up.