UPDATE: Monday, 5:19 p.m.:
Ravens General Manager and Executive Vice President Ozzie Newsome is back to work.
"It's good to see Ozzie's here. He's working. He's been here all afternoon working," Head Coach John Harbaugh said to open his Monday press conference.
"He's back and he has a clean bill of health. I don't think we know exactly what caused the situation yesterday, but it wasn't anything serious."
Harbaugh didn't find out about Newsome's health issue Sunday until after talking to the team and the media following the game. He immediately went to see him.
"They had done all the tests, so they didn't think it was anything serious," Harbaugh said. "But they had to keep him overnight for observation to make sure."
Newsome told Harbaugh that he went through tests "pretty much all night" at a nearby hospital.
UPDATE: Monday, 10:03 a.m.:
Ravens General Manager and Executive Vice President Ozzie Newsome is on his way back to Baltimore this morning and he said he is "feeling fine."
Newsome is expected to be back in the Ravens office and on the treadmill soon.
Ravens General Manager and Executive Vice President Ozzie Newsome did not leave with the team from Chicago after the 23-20 overtime loss. The team has released this statement:
"Ozzie Newsome did not feel well after today's game and a team doctor recommended that Ozzie not fly tonight."
According to a WNST report, Newsome left Soldier Field in an ambulance after sweating profusely after the game. It was believed to be precautionary.
The Chicago Tribune reported that security at the stadium stopped employees from using the hallway to load a person from the Ravens onto an ambulance.
Newsome, 57, does not have any known medical conditions. The Hall of Fame tight end has been the Ravens' general manager since 2002.