With summer beating down on Southern Arizona, you'd think the Town to Tough to Die would be the Town to Hot to Handle, June through September.The sweltering temps can be tough on tourism."Tourism is a tricky business to begin with," said Robert Davenport, manager for Good Enough Mine Tour & Trolley Tours.The heat has historically been a hindrance, for sure, but business owners in Tombstone say over the past four years, tourism has picked up duri…