The fires in California are heartbreaking and terrifying. Because I think there are enough hellscape fire photos already circulating, here is a smoke free photo of Ventura harbor on better days, plus a pelican. 
In addition to the completely unsettling feeling of not knowing if and when and where the winds will shift the fires to, there are a number of health effects that come from inhaling all that smoke. Wildfire smoke is a mixture of particles from burning vegetation, burning building materials, and anything else that’s burning. According to the CDC, “wildfire smoke can make anyone sick. Even someone who is healthy can get sick if there is enough smoke in the air.” Inhalation can have immediate health effects, including coughing, asthma, chest pain, headaches, and more. People who are more likely to experience health effects include older adults, pregnant women, children, and people with preexisting respiratory and heart conditions.
So what can you do, besides sigh loudly in despair every few minutes? Limit your time spent outside, and keep your windows and doors closed. Other CDC recommendations:
Do not add to indoor pollution. When smoke levels are high, do not use anything that burns, such as candles and fireplaces. Do not vacuum, because vacuuming stirs up particles already inside your home. Do not smoke tobacco or other products, because smoking puts even more pollution into the air.
Run an air conditioner if you have one, but keep the fresh-air intake closed and the filter clean to prevent outdoor smoke from getting inside.
Do not rely on dust masks for protection. Paper “comfort” or “dust” masks commonly found at hardware stores trap large particles, such as sawdust. These masks will not protect your lungs from smoke. An “N95” mask, properly worn, will offer some protection. If you decide to keep a mask on hand, see the Respirator Fact Sheet provided by CDC’s National Institute for Occupational Safety and Health.
Also, keep an eye on your pets for breathing trouble. And remember that even if the air outside looks clear, it’s unlikely to be free from harmful particles.
More resources:
One wild fire produces more greenhouse gas than every car in the US running for a year. When will CA be held accountable for this reckless production of CO2 and other climate-changing pollution?