As the Bay Area swelters under a heat wave, a spare the air alert has been extended through Wednesday, the Bay Area Air Quality Management District announced Tuesday. The alert, which was issued for smog,

The Bay Area Air Quality Management District has announced Thursday will be the fourth straight day a Spare the Air alert is in effect in the region due to hot weather and weak winds that will combine with motor vehicle exhaust to create unhealthy levels of smog.

An excessive heat warning will remain in place in the Bay Area through late Friday evening as hot temperatures continue to scorch the region.

High temperatures and light winds, combined with vehicle exhaust, will result in unhealthy air quality around the Bay Area for the next two days, air district officials said.