Responding to a Freedom of Information Act request, the Chicago Fire Department provided four years of data for each opioid-related EMS call it received since 2014. The data provided did not include addresses, but the data was grouped into roughly eight-block-by-eight-block segments across the city. Click on each year to see how the number of calls changed. The larger the gray circle ( ), the more EMS crews were called to that part of the city for opioid-related incidents.

The map also shows opioid-related deaths over those years. The colors correspond to deaths in heroin and no Fentanyl was present ( ), Fentanyl and no heroin was present ( ), both were present ( ) and neither Fentanyl nor heroin were present ( ).