I'm BFing at the moment but going to have to introduce some formula feeds as I need to leave my daughter (8w) for a few hours and I can't express enough milk. I've just read the formula advice which sayd you should make up the formula fresh for each feed. So boil the kettle, let it cool then add the formula then cool and feed!?? All while she's screaming because she's hungry sounds very stressful. 
Is this ok......boil the kettle and cool quickly, put the boiled water into the bottles and put them at the back of the fridge, then when she's ready, add the formula and warm?? 