Tesla's 'bioweapon defense' mode helps owners combat wildfire smoke.

Tesla owners are using the "bioweapon defense mode" in their cars, which includes HEPA air filters and positive pressure, to deal with the thick smoke from wildfires sweeping across North America. The mode acts as an air pressure buffer on top of the usual HEPA filtration, similar to the positive ventilation used in surgical facilities to keep any pollutants out. Tesla added intense air filtration to three of its models years ago, and drivers are finding them useful for unhealthy air.