Elgin, IL – Six people were treated for carbon monoxide poisoning at an east-side two-flat after one man came in to Sherman Hospital and reported he was not feeling well, authorities said.

Once Sherman staff determined that the man was suffering from carbon monoxide poisoning, they contacted the Elgin Fire Department, which was dispatched to the man’s home at 1:45 p.m. Sunday, said fire department Battalion Chief Bryan McMahan.

Firefighters arriving at the two-flat, at 450-452 St. Charles St., found five other residents affected by high levels of carbon monoxide in both units of the home, fire officials said.

“Initial readings were 100 parts per million, and anything over 70 ppm is immediately dangerous to life or health,” McMahan said.

Carbon monoxide detectors begin sounding at 30 ppm, he added.

However, carbon monoxide detectors were not present, officials said. Although the units’ owner told officials he had installed carbon monoxide detectors in the building, he did not know where they were now or why they may have been uninstalled. The home was red-tagged by city building inspection officials until the carbon monoxide problem could solved, authorities said.

The first patient was taken to Advocate Lutheran General Hospital in Park Ridge for treatment. Further information about conditions was not immediately available.