Ozone readings are climbing, especially in Fresno, so sports participants should pay close attention to the forecasts from day to day in late August and early September.

But now there's another reason to be more aware of air quality. Forest fires are burning south, east and west of the San Joaquin Valley, meaning smoke and PM-2.5 could be wafting into this region.

If you can smell smoke, the PM-2.5 is probably pretty thick in the air. The double whammy of smoke and ozone is hard on lungs.

Consider suspending sports or band practice -- or any other vigorous outdoor exercise -- for a day or so until the air clears.