Thanks girls - very interesting as I thinking bout breast milk and its certainly not heated up! lol
Actually it is heated - 37 degrees at body temperature!

I used to warm them in the microwave. The danger with that though (and why the hospital doesn't recommend it) is because it doesn't heat evenly. I just made sure I would shake it really well before I gave it to them.

Mine were precious little bundles too that totally refused their bottle if it wasn't a "perfect temperature".