By default, I have to give my baby girl cows milk by the middle of this week since my freezer stash is depleted and I can't pump enough anymore. How did you switch to cow milk? And did you heat up the cow milk? If so, how? Put a bottle in the bottle warmer? I want to use the como tomo bottles. This all seems foreign to me since I used the Kiinde bottle system for my girl so never used anything other than bags. Thanks for any advice!