A brush fire in the Lakeside area grew to more than 850 acres Wednesday, which kept Cal Fire firefighters on the scene and evacuees from accessing their property for a second day.

Face masks, such as N-95s and KN-95s, as well as indoor air filtration will help with the smoke and particulate matter, experts said.

The fire was about 25% contained and officials said they planned to drop firefighters onto the steep terrain by helicopter.