To become aware of your indoor air quality index is to enter a realm where the invisible becomes something you can never unsee. Until I wrote about my quest for good air in my Brooklyn apartment, I didn’t know air quality monitors even existed. Now I couldn’t live without them.

We humans evolved to respond to changes in temperature, precipitation, and wind. Bad air is silent and often odorless, but long-term exposure to certain vapors, particulates, and high levels of CO2 can impact cognition and make us vulnerable to certain cancers, as well as heart and respiratory diseases. Reading the daily temperature and looking at weather forecasts prepares us for what’s to come, but checking your air quality might be the biggest step you make in improving your health.

These air quality monitors were tested in two locations: a 130-plus-year-old Brooklyn apartment with a gas stove in a building that is undergoing construction, and a cabin in the Maine woods that uses an electric stove. There were two cats, a dog, and two people during the entire testing period. I had various air purifiers running at all times. Neither location had central air or HVAC with MERV filters, nor did they have over-stove exhaust fans that could remove fumes to the outside. In both locations, it was cooking on the stovetop that produced the worst air. These monitors were used both on days with excellent outdoor air and days when air quality was in the moderate zone, above 50 on the US Air Quality Index.

For more ways to keep your air quality in check, take a look at our guides to Best Air Purifiers and Best Robot Vacuums.

Power up with unlimited access to WIRED. Get best-in-class reporting that’s too important to ignore for just $2.50 $1 per month for 1 year. Includes unlimited digital access and exclusive subscriber-only content. Subscribe Today.

If you buy something using links in our stories, we may earn a commission. This helps support our journalism. Learn more. Please also consider subscribing to WIRED