If you have issues related to asthma or heart disease, it’s been one week since the haze set in, and it’s best to skip the stroll and stay cool within. That has been the advice of the Wisconsin Department of Natural Resources and health officials since last Tuesday, when the state was first placed under an Air Quality Alert due to the Canadian wildfires. The DNR extended the alert for one more day, ending at noon on Tuesday. The Air Quality Index (AQI) has bounced between Unhealthy for Sensitive Groups and Unhealthy, though some parts of the state have reached as high as the Very Unhealthy level. When the PM2.5 (particulate matter with a diameter of 2.5 microns or less) level is rated as unhealthy, it can cause health issues, including eye, nose, and throat irritation, coughing, and shortness of breath. People with heart or lung disease, older adults, and children should avoid prolonged or heavy exertion, while everybody else should reduce it.