How do mobile phones send texts?

Mobile phones use micro waves to send infortmation from one mobile phone to another. They are sent to a phone mast and then sent to the other phone, people are worried on what effects this will cause because if micro waves can cook things like a jacket potato in 8 minutes all the way through what affect could the micro wave be having on our brains? Even though the waves are slightly different, if they were the same i am sure people who use phones on a regular basis would have melted brains by now.