Doctors are so busy ambulance drivers are told to bypass eight area hospitals if there's time to safely get their patient to another facility.
Northwestern Memorial Hospital is one of the hospitals where patients are being rerouted because the emergency rooms are too full. So far this season, the flu has claimed seven lives in Indiana and five in Illinois.
A sneeze here, a cough there. Everywhere you look, it seems someone is sick.
"He was coughing a lot during the past week. Not sure what's going on," said Keo Thach.
Thach brought her husband to Cook County Hospital. The emergency room there is seeing 50-to-70 suspected flu cases each day. That's on top of the hospital's nearly 400 regular daily ER visits. County continues to treat all patients.
But eight Chicago-area hospitals have been on bypass for at least part of the night because their emergency rooms are overwhelmed.
"If you're throwing up, you can't keep down any fluids for more than a day, you're feeling weak, having trouble breathing, or chest pains we'd encourage people to come in," said Dr. Robert Feldman, Cook County Hospital.
Forty-one states are now reporting widespread flu activity.
The Centers for Disease Control says in high flu states 70 -80 percent of the coughs around you are from the flu.
Each cough, sneeze and touch puts non-carriers at risk.
The virus can survive 2 -8 hours on metal or plastic. Think about that next time you ride the bus.
In an elevator, one sneeze can spray flu, in droplets, up to 20 feet, in your lungs and coating the doors and buttons.
Influenza is so contagious, hospitals are distributing masks and isolating carriers.
"We make sure they're in their own room, separate from other patients, so it doesn't get spread from person to person," Dr. Feldman said.
Doctors say that as bad as the flu is this year, they're not seeing as many, or as sick, patients as they did during the H1N1 outbreak in 2009.
The best advice is to wash your hands frequently and there's still time to get the flu vaccine.