We did what Emma did and boiled the kettle, measured out the bottles and let them cool. We would then make the bottles up as and when we needed them.
When we switched to a reflux formula, the powder tended to disolve better in cold, so kept our bottles refrigerated.
Many people do it differently, some will boil the kettle, make the feed and then cool down under a cold tap, but it is what ever is best for you.