It was a godsend when our pediatrican told us this. He said just use powdered formula, mix it with room temperature water at feeding time. No need to refrigerate premixed formula, no need to heat it up, no need to carry it around in a cooler when you're on the go.
We used silicone bottles along with a bottle warmer for refrigerated breast milk though.
Pro tip: buy a damned bottle warmer in that situation. Don’t try to get by putting hot water in a cup and putting the bottle in that. The $50 is worth your sanity when there’s a crying baby.
If that doesn’t make sense to you as a microbiologist, you should let the US FDA know.
https://www.fda.gov/food/foodborne-pathogens/cronobacter-sak...
https://www.fda.gov/food/foodborne-pathogens/cronobacter-sak...
But you do you.
mostly because it eliminated the potential to make the liquid too hot for the child.
but glad we did it that way now anyway.