A Southwest spokesperson said a passenger on Flight 577 was removed from the flight for "poking her seatmate with a pen to stop him from snoring."
The Chicago Fire Department was called to evaluate the man, who was not seriously injured. It appears he was able to continue on the flight to New Hampshire.
The flight was scheduled to leave Midway Airport at 1:15 p.m. Thursday afternoon, but was delayed two hours due to the incident.
Southwest said the passenger who was removed will be accommodated on another flight.
There's no word yet of any charges being filed.