The Bay Area Air Quality Management District has issued a Spare the Air alert for Friday because of elevated levels of smog expected as a result of high temperatures and light winds in the region.
The air district also issued an air quality advisory because of possible smoke from wildfires elsewhere in Northern California like the Walker Fire in Plumas County that may drift into the Bay Area, mostly at higher elevations.
A Spare the Air alert was also issued for Thursday because of excessive smog, and Friday's alert is the 14th so far in the summer season.
On Spare the Air days, the air district encourages people to find alternatives to driving solo, such as carpooling, taking public transit or working from home.
Pollution from smog, or ozone, can cause throat irritation, congestion, chest pain and other medical problems. Outdoor exercise on Spare the Air days is recommended only in the early morning hours, when smog concentrations are lower, according to the air district.
People can find out when a Spare the Air alert is in effect by visiting sparetheair.org, calling 800-HELP-AIR (4357-247), downloading the Spare the Air smartphone app for iPhone or Android devices or connecting with Spare the Air on Facebook, Twitter or YouTube.