Wonder if you can help me. I'm combining expressing with formula and up until now have been using readymade. This is not very cost effective though so want to start using powder. I have read how to make the bottle up, but what about if I go out? At the moment with the readymade stuff I warm up a bottle and then put it in an insulated Tommee Tippee carrier which keeps it warm for 4 hours. Can I do the same with the powdered once it's made up? Is that a silly question? I'm not sure why I'm finding it so confusing! Any tips on formula would be very much appreciated. Have got two cartons of readymade left and then it's bite the bullet powder time! Eeek!