It's wildfire season—and something about this year is especially sinister. West Coasters experienced days of hazy orange skies in early September as a result of the burning wildfires. As COVID-19 still looms, threatening our respiratory systems, now too does the smoke in the air. What is this smoke made of, and how does breathing it in affect our lungs and bodies? To find out, Host Dr. Alok Patel speaks with an atmospheric scientist, a pulmonologist, and a pair of veteran engineers who are experts in effective face masks to learn about the composition of wildfire smoke, what that smoke does to our lungs and bodies, and what we can do to protect ourselves. Learn more about NOVA and subscribe to our YouTube channel.