South Portland, ME – One person is recovering after being exposed Monday to high levels of carbon monoxide.

First responders were called Monday afternoon to the Howard Johnson hotel in South Portland and found a person unconscious and vomiting in a stairwell.

The hotel was evacuated.

Fire crews found high levels of carbon monoxide near the furnace.

Officials said the levels of CO found near the furnace can be life-threatening in as few as three hours.

Crews secured the furnace and ventilated the building.

No one else was injured.