My ds is 6 weeks old. He is breastfedwith some pumped bottles and some formula bottles. At first we were very diligent about warming up his bottles, but then discovered that he didn't seem to care whether it was warm or not. So now we just take it staight from the cooler/refrigerator and give it to him. Is this okay? Is the reason they say to warm them up just so they'll take it easier or for some real medical reason?

i give ds bottles at room temp or warmed up, i think straight from the fridge might be too cold on their little bellies, but i don't know why they say not straight from the fridge.
i do wait for my boiled water to cool then add formula to make fresh bottles every time rather than making up bottles and storing them in the fridge as i read string in fridge causes the milk to breed more germs this way than made fresh bottles i hope this makes sense. cooled bottles of boiled water remain sterile for 24 hours and don't need to be kept in the fridge either.

The reason is the cool milk can make them have a belly ache. I know they don't recommend using the microwave to heat up bottles but we have a very top of the line microwave and I do use it to heat up her bottles. I don't use microwaves at other people's houses because they have regular microwaves and it doesn't heat the bottle evenly.

Well my son is 7 months, I still warm up the bottle, only if its right out the fridge, and I do use a microwave, i hate the bottle warmer, it takes too long...I dont "warm it" i just take the chill off now, But up until he was about 4 months i made it warm, because it does give them a belly ache :wave:

I also only warm it enough to take the chill off. I use a microwave. If you use a microwave, make sure you shake it very well. If you nuke it too long, it can destroy some of the enzymes.

I use a microwave too - just to take the chill off - it is like room temp. ish.... I use chopsticks (lol) to stir the formula up to make sure there are not hot spots, and then feed her... If your baby doesn't mind it cold - that is GREAT! I sometimes make sure the formula is on the cooler side on Hot Days!

We use room temp bottled water and mix it with the powder on demand. With my first, I'd make enough for one day and then warm them up as needed, but warming them I think is a pain in the butt and she likes room temp fine.