DD started off with HOT HOT bottles- she wouldnt drink them unless they were hot, then one day when she was teething a bit, she started fussing on the hot ones, i had one in the fridge ready to heat up and i thought, what they heck and gave it to her cold, she loved it and drank it!! Now she goes with cold, room temp or hot, depending how she feels at the time lol, but usually room temp. Same as the others, i just put cooled water in the bottle and then add the formula and she drinks it like that. Its much handier when going out!!!

But i do find she likes her bed time bottle a bit warm, like Mel says, i think it helps them go to sleep a bit better!