The exceptional heat wave in Europe, with temperatures well above average, is also starting to affect Italian emergency rooms, with a 10-15% rise in visits in big cities, health officials said Friday.     "We can estimate a 10-15% increase in emergency department visits in large cities," says Alessandro Riccardi, president of the Italian Society of Emergency Medicine (Simeu).     He also clarified that, for now, "the increase in visits remains limited and there is no cause for alarm." These