Ozone is formed when pollutants emitted by industrial facilities, power plants, motor vehicle exhaust and other sources react to the presence of heat and sunlight. Since heat and sunlight drive ozone formation, warm sunny days have more ozone than cool or cloudy days, and ozone levels are generally much lower in the mornings.

To avoid health risks associated with ozone:

• Reduce exposure by playing and exercising outdoors before noon
• Limit vehicle idling when possible
• Curtail daytime driving
• Refuel cars and gasoline-powered equipment as late in the day as possible
• Carpool
• Combine trips
• Limit vehicle idling by avoiding drive-throughs and excessive idling caused by long wait times making left-hand turns