similac alimentum rtf

Priscilla
Hiii i just switched my babys formula to similac alimentum due to reflux but im confused on the ready to feed is it really necessary to refrigerate after opening why can it not be at room temperature? I understand it has to be used in 48 hours but why does it have to be refrigerated? Im pouring the milk in babys bottle she is not drinking from the main bottle so im confused Please someone guide me