Dennis, MA – Five members of a Dennis family who unknowingly suffered from carbon monoxide poisoning were sent to the hospital Saturday, according to the Dennis fire department. Dennis Fire Captain Dan O’Connell said four men, ages 65, 63, 56, and 31, and a woman, 53, were still in Cape Cod Hospital Saturday night and two were being transferred to a hyperbaric chamber. O’Connell said the family was alerted when a daughter who does not live in the home visited Friday and woke up Saturday with flu-like symptoms. Her father went to pick up two detectors around 1:20 pm because the family’s previous carbon monoxide detectors had dead batteries. When he plugged in the detectors, their alarms sounded, showing significant carbon monoxide levels in the home. Dennis fire officials said the high levels were likely caused by a malfunctioning heating boiler in the basement.