Hot, sunny days mean more than summer vacations and lazy days by the pool. They might also make you sick.

  Thats because warm temperatures, clear skies, and little or no wind provide the perfect conditions for higher ozone levels. The Shelby County Health Department released a Code Orange ozone advisory June 23, meaning ozone levels were high enough to make certain people sick. High levels of ozone pose a health hazard.

  Code Orange means ozone levels can be dangerous for sensitive groups people who spend a lot of time outdoors and people with respiratory disease, such as asthma. Under an orange advisory, these people should limit their time outdoors, particularly if they are physically exerting themselves. 

  How long depends on the individual, said Brenda Ward, public relations director for the Shelby County Health Department. Someone with severe respiratory problems may be out 15 minutes and will have a problem.

  The Environmental Protection Agency has five different categories of ozone levels. (See chart.) Orange is the third worst. Purple represents the most dangerous levels. Shelby County has never reached this category, but it has reached Code Red the second worst one time a few years ago, Ward said. 

  Ozone, a colorless gas that can be found in the air, is a major element of urban smog. Ozone can limit a persons ability to take a deep breath, and it can cause coughing, throat irritation, and breathing discomfort. There is also evidence that ozone can lower resistance to respiratory disease (such as pneumonia), damage lung tissue, and aggravate chronic lung disease (such as asthma or bronchitis), according to the Environmental Protection Agency. 

  Many individuals with a chronic pulmonary disease such as COPD (Chronic Obstructive Pulmonary Disease) often complain that humidity and summer heat have a negative effect on their breathing, said Larry Hopper, director of respiratory services for Baptist Memorial Hospital-Memphis. It has been found that by daily tracking the environment pollutant alerts, such as the ozone level, they have the opportunity to reduce their pulmonary complications during the summer months, Hopper said. 

  Ozone air pollution forms when emissions from motor vehicles, power plants, and industry react with sunlight. It is the most widespread air pollutant, affecting millions of people all over the United States not just in big cities, according to the American Lung Association. 

  Parents should look for warning signs of undiagnosed asthma in their children, such as coughing regularly, and shortness of breath when exercising. Let your pediatrician know if you notice any signs. Children with asthma are particularly sensitive to ozone pollution. In general, children are more vulnerable to air pollution than adults because their respiratory defenses are not fully formed, according to the American Lung Association. Their airways are smaller, and more likely to become blocked when irritated. They breathe more rapidly, taking in more pollution per pound of body weight. Children also spend a lot of time outdoors. 

  People who are highly sensitive to higher ozone levels should make sure they take the medications prescribed for their condition correctly especially before spending time outdoors, Hopper said. 

  Keep track of air pollution levels. If the air quality is unhealthy, try to limit the amount of time spent outdoors in vigorous play. Plan the most strenuous activities for the early morning hours, before ozone levels climb, according to the American Lung Association. Keep all outdoor activities as far as possible from busy roadways and other sources of pollution. Maintain proper ventilation in your home when doing tasks such as painting or cleaning with industrial products. An air purification system in your home can help keep air clean and pollutant free, Hopper said. 

  During the summer, you can find information about daily ozone levels from your local or state air pollution control agency, which is usually the health department. Some agencies will also provide a forecast for the next day. Air quality information may be included as part of the weather forecast on television, radio, or newspaper. Many states have Web sites on the Internet where they post ozone forecasts. 

  Please visit the Shelby County Health Departments Web site for more information about ozone levels.

  If you need help locating a source of air quality information, you may call your local Lung Association at 1-800-LUNG-USA.