For the second time in three months, students at a Bangor beauty school have been taken to the hospital because of a carbon monoxide scare.Bangor Assistant Fire Chief Rick Cheverie says they got a call around 9:40 Wednesday morning from Empire Beauty School saying there was a gas odor in the building. He says the school was evacuated and 12 wound up in local hospitals with symptoms of carbon monoxide poisoning. In November, a similar incident sent some of the school’s students to hospitals.The school has carbon monoxide detectors, something Cheverie says all of us should have in our homes and offices. “They’re relatively inexpensive but they are a tremendous benefit. When those go into alarm it’s time to get out, air out and call in the professionals.”Fire officials believe a heating unit is to blame for the carbon monoxide leak.A state inspector will look into it.