Several employees working at the Crossroad Commons' Kohl's reported feeling nauseous and four began vomiting Tuesday morning. Those are common symptoms of carbon monoxide poisoning.

Kohl's employees evacuated everyone and called the Plover Fire Department around 10 a.m. Firefighters checked the building and didn't find any CO levels, but Fire Department officials say Kohl's did the right thing calling them in.

"They got the right people there, they got their people out and closed the store for a short period of time and had the store tested," says Chief Tim Kluck.

One employee sought medical care. According to Kohl's that person was sent home without any complications. Kohl's officials say they're not sure what fumes or chemicals caused the employees to become ill, but the damaged heater is being checked and repaired.

Even though Kohl's is not believed to have a carbon monoxide leak, Plover's Fire Chief says this is a prime time of year for carbon monoxide poisoning. He says to keep your family safe, get your heating unit checked out and get a carbon monoxide detector, since CO can't be smelled or seen.