CHARLOTTE, N.C. -- Heat took its toll on people in area Thursday. Carolinas Medical Center reported seven patients were seen for heat-related illnesses calls during the hottest hours of the day, including three athletes who were competing in track and field events at the University of North Carolina at Charlotte.

And not only was the air hot, it was unhealthy too. The ozone is in Code Orange, and Dr. John Klimas, who treats asthma, said the ozone level is bad for asthma patients and people with allergies.

"It actually triggers irritating rashes, but also can push allergic reactions to be worse, so if you have allergies it actually makes it worse as well," Klimas said.

Currently efforts are underway to clean up the air in the Charlotte region.

Industrial thread company American and Efird in Gaston County is doing its part. Employees get incentives for carpooling and they can work from home, avoiding a car trip to and from the office. Also, an anti-idling policy will be implemented for delivery trucks.

Company Spokesman John Eapen said meeting environmental air quality standards is a must for businesses to succeed.

"It will be tough for manufacturing in this area to get environmental permits either for a new plant or to expand their operations, so it is very, very important," he said.

Federal law requires the Charlotte region to improve air quality. If that doesn't happen, much-needed federal transportation dollars could be lost.

But Klimas and others agree that making Charlotte's bad air better is a challenge.

"You have economic development, which is great – Charlotte has thrived over the last 20 to 30 years – but you also have the side effect of pollution and other situations," Klimas said.

The Charlotte region has until 2010 to clean up the dirty air and meet the Environmental Protection Agency air quality standards. County leaders said progress has been made, but there is still much to be done.

As for people with allergies and asthma, health experts say the best way to stay safe during days with high ozone levels is to stay inside.