California’s Air Quality Is Poor. Here’s How to Protect Yourself.

SAN FRANCISCO — Jennifer Krasner’s 4-year-old daughter had been coughing for days. Ms. Krasner and her family live 20 minutes north of San Francisco, in Mill Valley, Calif., not close to any fire but wreathed in smoke nonetheless, with her house and car dusted with ash.

“I had to get her tested for Covid because she’s been coughing so much,” she said Thursday, “but it turned out her lungs were just irritated from all the smoke.”

Across San Francisco Bay to the southeast, in Alameda, Monica Chellam’s daughter, also 4, asked Wednesday why it was so dark. “I told her the sun was blocked by smoke,” Ms. Chellam said.

“She turned to me and asked, ‘Is this how the dinosaurs died?’”

Children aren’t the only ones coughing. And they’re not the only ones with questions about the smoke that is spreading misery around the West. Here are some key facts and tips on what you can do.