Chicago’s three-day heat wave might have fueled a surge in opioid overdoses over the weekend, health experts say.
Sixty opioid overdoses were reported Friday and Saturday — including more than 37 Saturday alone — triggering the city’s spike alert system, the Chicago Department of Public Health said.
When surges occur, public health officials and community partners canvass affected neighborhoods to pass out naloxone, a medication used to rapidly reverse the effects of an opioid overdose. They also provide information on opioid use and connect people to treatment if they want it.
Weather officials issued an extreme heat warning that began Saturday morning and was in effect through Monday night. Saturday’s high reached 95 degrees with a heat index recorded at 106, the National Weather Service said.
The heat wave may have also played a role in the spike in overdoses, according to Jenny Hau, medical director of behavioral health and interim deputy commissioner at CDPH.
“We always see a seasonal increase in the number of overdoses in Chicago, as well as many other places in this country and around the world,” Hau said. “So certainly heat has a pretty close correlation in terms of the amount of overdose activities.”
Saturday’s surge marked the first time this year the spike alert system was activated. Overall, health officials note that the number of opioid overdoses has been declining in recent years.
This year’s average of 22 overdoses per day is a significant decrease from previous years, Hau said.
The decrease in overdoses has also led public health officials to lower the spike alert threshold. Last year, the system was triggered when more than 50 overdoses were recorded over a 24-hour period. This year the threshold is at 37 overdoses.
Because most overdoses happen outdoors, there tends to be an increase in usage during the summer months, Hau said. To help prevent spikes, public health officials collect drug samples during outbreaks to improve clinical guidance and quickly deploy resources to the communities experiencing the surge.
“Public health is always about prevention, right? So the thing that we’re really trying to prevent is death from overdoses. And we’ve seen fatalities decreased significantly over the course of the last couple of years.” Hau said.
The majority of overdoses happen on the city’s West Side, Hau said. Thirty-four percent of EMS calls for overdoses were in five Chicago neighborhoods, including East Garfield Park, West Garfield Park, North Lawndale, Austin and Humboldt Park.
Most overdoses are caused by synthetic opioids — particularly fentanyl.
“When we do community-based drug checking, we look at what the drug was sold as, and then what it actually contains,” Hau said. “Drugs can be sold as heroin, fentanyl or dope, but you can expect that they would all contain some combination of synthetic opioids.”
In 2021, the city hit an all-time high, with more than 1,400 overdose deaths. There were 1,322 deaths in 2023.