Hot weather expected to continue into the weekend has prompted the Bay Area Air Quality Management District to issue another Spare the Air alert for Saturday.
Triple-digit temperatures in many inland parts of the region are expected to combine with vehicle exhaust to create unhealthy levels of smog, or ozone. Smoke from a wildfire in southern Oregon has also been affecting air quality in the Bay Area this week, according to the air district.
When smog pollution is at unhealthy levels, it can cause throat irritation, congestion and chest pain, and is particularly dangerous for young children, seniors and people with respiratory or heart conditions.
The air district encourages anyone doing outdoor exercise on a Spare the Air day to do so in the early morning hours when smog levels are lower.