The Colorado Department of Public Health and Environment has issued the following. WHAT. Air Quality Health Advisory for Wildfire Smoke. WHERE. Delta, Montrose and southern Mesa Counties. Locations include, but are not limited to Delta, Montrose and Nucla. WHEN. 400 PM Thursday July 10 to 900 AM Friday July 11 IMPACTS. Multiple wildfires across the region will produce moderate to heavy smoke across the forecast region through at least early Friday morning. HEALTH INFORMATION. Public Health Recommendations: If smoke is thick or becomes thick in your neighborhood you may want to remain indoors. This is especially true for those with heart disease, respiratory illnesses, the very young, and older adults. Consider limiting outdoor activity when moderate to heavy smoke is present. Consider relocating temporarily if smoke is present indoors and is making you ill. If visibility is less than 5 miles in smoke in your neighborhood, smoke has reached levels that are unhealthy.