Why you should drink warm water with lemon

We have all been through rituals of doing something because someone said it was good for us. We have all heard that warm water and lemon is a good alternative to coffee. Do we really know why though? We had a pouring jug in our fridge all through the summer with lemon slices and chilled water as a replacement to fruit squash. I think it will be returning after reading this great little article Why you should drink warm water with lemon