A total of 10 people were taken to area hospitals Thursday after high levels of carbon monoxide were detected at two separate residences in Baltimore County.
Fire officials believe malfunctioning furnaces were responsible for high levels of the gas at both homes.
The Baltimore County Fire Department first responded to the 1600 block of Manor Road around 5:43 a.m. after someone reported an unconscious seizure patient, according to fire officials.
When emergency personnel arrived, they found five other people suffering from suspected carbon monoxide poisoning symptoms.
All six people were taken to Shock Trauma for treatment and evaluation.
Carbon monoxide levels inside the home were 600 parts per million, according to fire officials. Safe levels of carbon monoxide are below 30 parts per million.
Later Thursday morning, emergency personnel were dispatched to the 7900 block of St. Monica Drive in North Point.
Personnel detected high levels of carbon monoxide, registering at 120 parts per million, at the second home.
Four people were transported from the North Point home to Bayview Medical Center for evaluation, fire officials said.
Neither home had carbon monoxide monitoring devices installed.