Prompted by another thread - I remember feeling v paranoid about this when dd was first born until an Aussie midwife said that they all do it over there, even in the hospitals!
From that day on I used the microwave, and tbh everyone I know does the same despite the "hot spot" warnings. I do feel if you shake the bottle thoroughly and then leave it for at least a minute there is no issue.
So who did it and who used bottle warmers/warm water, and why?