In indoor crowded spaces, CO2 is often 2000 ppm or higher (background is now around 450). We might notice but just deal with it. In the past that meant getting sleepy at a lecture or that sort of thing, but today I’d consider it risky. I still wear an N95 mask whenever I’m in a public indoor space.
In indoor crowded spaces, CO2 is often 2000 ppm or higher (background is now around 450). We might notice but just deal with it. In the past that meant getting sleepy at a lecture or that sort of thing, but today I’d consider it risky. I still wear an N95 mask whenever I’m in a public indoor space.