The little ones, especially, forget to drink or to tell you that they need to drink. Common symptoms of dehydration are crankiness, headaches, aches in the joints and weariness. If your child says he/she is thirsty, dehydration has already begun. Avert this, simply make sure that you child has constant access to a great drinking bottle, one made from sound materials incorporating great design. Most baby bottles and drinking cups are made from Polycarbonate which contains a volatile substance called BPA that readily leach into the liquids in these vessels. An environmental oestrogen, also known as an endocrine disrupter is a growing world wide concern. Studies have linked low-dose BPA exposure with such effects as: permanent changes to genital tract; increase prostate weight; decline in testosterone; breast cells predisposed to cancer; prostate cells more sensitive to hormones and cancer; and hyperactivity.