I also have a friend who does this, her name's Therese, lovely girl. Irish. She claims that it is a good thing to do, but I have never really seen the point myself. Drinking it is like drinking warm milk. OK, but better with a little sugar or tea. After all, it may purify the system, but surely that is just the heat, in which case take some flavour ie a teabag, whereas if it is the water, then you may as well drink it cold. Either way, better with flavour.