Tanja Sopys waited for her brother, David, to arrive at her South Side home in early July.Instead, a Chicago Transit Authority worker rang her doorbell after finding her brother’s medications left behind on a bus.“My wife takes that, so I know how important it is,” the worker could be heard sa ying in her home security video. David Sopys, 46, died due to extreme heat this summer in Chicago.Provided It would be days before Tanja Sopys would learn her brother died that same day — July 1. She wasn’t notified about his death until after an autopsy was performed, determining he died from hyperthermia due to heat exposure while Chicago was under an extreme heat warning.Tanja Sopys pieced together David's whereabouts in the days leading up to his death. He’d left the south suburban mental health rehabilitation facility where he had been living. At some point, he ended up at a Chicago hospital. When she was finally able to talk to her brother by phone, he told her he was planning to live at a different facility on the North Side, but he wouldn’t provide specifics.He asked her for money. “I’m like, ‘Well, David, why don’t you just come here and get it,’” Tanja Sopys recalls telling her brother. “He was like, ‘I’ll come over there.’”That was the last time she heard from him. David Sopys, 46, died 31 years after his own father died at the same age from the heat.“He was a ‘95 heat stroke victim,” Tanja Sopys said about their father. ”So he died the same way — from the heat.”Their father was among the hundreds in Chicago who died during the deadly hot summer of 1995. More than three decades later and following reforms — such as how the National Weather Service warns the public about extreme heat by issuing advisories ahead of time — hundreds no longer die from extreme heat in Chicago.But now another Sopys is part of a spike in heat deaths in the Chicago area. More people — 16 — died from the heat in Cook County this summer than in any previous year in the last decade, according to a WBEZ and Chicago Sun-Times analysis of county data. Experts say heat-related deaths should be preventable and those who died from the heat this summer leave behind questions about what individuals and Chicago officials can do to adapt to and mitigate future stretches of extreme heat.“Essentially all heat-related deaths are preventable,” said Kristie Ebi, professor at the Center for Health and the Global Environment at the University of Washington. “And one needs a sense of the size of the problem to provide incentives, motivations for investments in heatwave early warning and response systems, in understanding the distribution of the vulnerable groups so that one could invest appropriately into the regions that have more vulnerable people.”Before this year, the most heat-related deaths the county had experienced in the past decade was eight, in 2022 and 2024, according to the analysis.The Cook County Medical Examiner's Office flags some deaths as "heat related" in its online case archive, which dates back to 2015. WBEZ and the Sun-Times looked at hundreds of deaths since 2015 and identified heat-related deaths by using that flag as well as cases mentioning a primary or secondary cause of death as "heat stress," "heat stroke" or "hyperthermia." Reporters then ruled out cases not tied to warm weather.Eleven of the 16 people who died from the heat this year either died or experienced symptoms that led to their deaths during a stretch of extreme heat and high humidity from June 29 to July 3, according to data from the Cook County medical examiner’s office. Chicago’s Office of Emergency Management and Communications issued an extreme heat warning on June 28 and then later extended the warning until July 3.During that stretch, the city experienced four consecutive days of high temperatures ranging from 92 to 95 degrees, with temperatures falling slightly to 88 degrees by July 3.A few of the people, like Sopys, were found outside, but others were found in homes with no working air conditioning.On July 2, when the temperature reached 95 degrees, David Gonzalez, 44, collapsed while moving out of a Chicago Lawn home, just blocks from where David Sopys was found the day before. Otto Kendzior, 63, was found Aug. 4 inside a car that had hot air running on a day when temperatures reached 86 degrees. Joseph W. Huff, of Oak Lawn, who was 65 and just settling into his retirement years, was among at least nine area residents who were found in their homes, according to records from the Cook County medical examiner’s office.In seven of those cases, including Huff’s death, investigators noted there weren’t any working air conditioners in the homes. In Evanston, Daniel Machnikowski, 69, was found next to an air conditioning unit that had not been installed. How the body enters heat strokeDuring extreme heat, the human body sends blood to its edges — like the arms and legs — to keep its central organs cool, said Dr. Sheetal Khedkar Rao, co-investigator at the University of Illinois Chicago’s Center for Extreme Conditions and Health Excellence. Some of the first signs of the heat altering a person’s body will be visible through rashes and swelling of the ankles.As the brain and heart get less blood, a person enters heat exhaustion, Rao said. A person will feel more fatigue, get headaches, experience cramps and could feel nauseous.“This is the stage where things can go in the wrong direction if you don’t act in a way to cool down,” Rao said, adding that a person’s condition can escalate to a heat stroke unless the person can hydrate and cool down.During a heat stroke, there's less blood flowing throughout the body because of how much the person has sweated, Rao said. At this point, a person’s brain, along with other organs like the heart, are getting very little blood. A change in a person’s mental state is associated with heat stroke and some individuals may feel confused, Rao said.An altered mental state was noted in at least three of this year’s heat-related Cook County deaths, according to county records.When a person is experiencing a heat stroke, their heart will beat even faster to get enough oxygen to the body but it’s doing so with less blood, Rao said. A person may not even sweat because the body has used up all of its fluids, she said. Still, their body temperature could be as hot as 104 degrees.“They may not even complain of thirst because their brain isn’t functioning normally, it hasn’t gotten enough blood flow,” Rao said. “If they have a fever and they’re overheated and they’re confused, that is an absolute emergency.”If a person’s body temperature is recorded, investigators use it to determine if a death was heat related, said Dr. Ponni Arunkumar, chief medical examiner at the Cook County medical examiner’s office. If the person’s body temperature is not known, that may lead to heat being recorded as a contributing factor rather than the primary cause of death, she said.Investigators are also looking for other factors like the temperature of the place where the person was found and if there were air conditioners, Arunkumar said.Many of those who died had recorded body temperatures that neared or exceeded 104 degrees, according to county records. David Sopys had a recorded temperature of 107 degrees when he arrived at Little Company of Mary Medical Center.Paramedics transported Sopys to the hospital after people called 911 at about 6:30 p.m. on July 1, reporting that he had fallen near 63rd Street and Campbell Avenue in the Chicago Lawn neighborhood. He was pronounced dead two hours later.Temperatures at Midway International Airport had reached 94 degrees that day.More vulnerable to heat injuryDuring an autopsy, investigators look for kidney damage to determine what role heat played in the death, Arunkumar said. They also check for any substances the person may have taken prior to the death.“Looking at all of that information, then we’ll determine whether the death is due to or related to heat,” Arunkumar said. “We are very aware that most of these deaths are preventable, so we keep our data transparent.”Rao said patients living with chronic conditions and those living in areas with little tree canopy can be most at risk for heat-related injuries. But Rao said heat-related injuries and deaths can happen even to unsuspecting healthy individuals. She urges patients to start hydrating before a heat wave starts. Dr. Sheetal Khedkar Rao, co-investigator at the University of Illinois Chicago’s Center for Extreme Conditions and Health Excellence.Anthony Vazquez/Sun-Times Medications for chronic conditions can work against the person’s body navigating extreme heat, Rao said. For example, diabetics could be taking diuretic medications, commonly known as water pills, which could exacerbate how much fluids a person is losing, Rao said.Heart patients on medications known as beta blockers, which slow the heart down, may not adjust to the heat because their heart can’t beat faster, Rao said.The heat is also particularly dangerous for people who have taken a substance, ranging from alcohol to drugs. In David Sopys’ case, an autopsy determined he had taken two medications typically used to treat mental health conditions, and traces of cocaine were also found.Cocaine is one of the substances that disrupts how the body distributes the blood to cool down the central organs, Rao said.“It also makes your heart rate go fast, and then your heart rate’s already going fast from the heat so it’s too much for your heart to handle,” Rao said.People experiencing homelessness are also more vulnerable to dehydration and heat stress, said Qi “Charles” Zhang, clinical director for the Street Medicine Institute, a nonprofit providing health care to the homeless across the country.“The body is already under stress because they’re unhoused and they don’t get regular meals, and on top of it, they don’t have regular access to clean water,” Zhang said.Shelter during extreme weatherAs the Chicago area underwent a four-day stretch with temperatures climbing into the 90s in early September, the city’s Garfield Community Service Center, a cooling center on the West Side, sat nearly empty during one of those mornings. Inside a community room lined with blue plastic chairs, two people waited to talk to a case worker about housing. Plastic water bottles were placed at a table near the entrance.Other cooling centers are even more underutilized. The South Chicago Center, 8650 S. Commercial Ave., and the Trina Davila Community Service Center, 4312 W. North Ave., each logged just three visitors during the heat wave from June 29 to July 3, according to records from the city’s Department of Family and Support Services. The Garfield Center, 10 S. Kedzie Ave., is pictured on Sept. 2, 2026, when the city was experiencing a four-day stretch of abnormally hot and humid temperatures. The Garfield Center is one of the places the city of Chicago uses as a cooling facility during extreme weather events.Elvia Malagón/Sun-Times It’s unclear if any of the people who died this summer tried to access a cooling center. David Sopys was among those who were found on the street. Another person, Stephanie Rodriguez, was found unresponsive at a bus stop before she was taken to an area hospital, according to records from the medical examiner.Chicago Street Medicine, which does medical outreach to encampments and public transit stations, has been in talks with city officials about improving accessibility of cooling centers, said Alexa Canning, vice president of operations for the group. They’ve urged the city to open a static 24-hour location when temperatures go beyond 95 degrees or below 30 degrees, she said.“We’ve seen that some of our patients have attempted to go to these warming and cooling centers and haven’t been able to access it for staffing issues or the sites are just closed,” Canning said, adding that they are also working to get information to patients since some don’t have access to the internet.The city also faces a funding crunch to expand these types of services amid cuts to federal programs and grants, said Ald. Maria Hadden (49th).“We’ve been looking to sustain what we have while we look for money to expand access,” Hadden said. “I think that there’s a conversation to be had, and we are having it, to pull in some of our business and philanthropic communities during this really challenging time under this federal administration.”Reducing emergency room visits during the heatHadden pushed in September for an ordinance to provide protections for outdoor workers during periods of extreme heat. But Hadden said they have so far faced opposition from the business and hospitality industries.She was behind the city’s cooling ordinance that calls for certain buildings to provide air conditioning in every unit or maintain an air-conditioned common area when the heat exceeds 80 degrees. But some of those who died this summer without air conditioning lived in homes or apartments that aren’t covered by the ordinance.“I do think the next step would be a cooling requirement ordinance for everyone, right,” Hadden said. “We don’t currently have that legislation in place … with the experiences that we’re seeing with our highest number of heat-related deaths this year that we’ve seen in a long time, I think we do need something like that.”Extreme heat was also found to be behind even more health issues like skin conditions and even traffic accidents, according to a Northwestern University study published this summer in Science Advances.The study looked at electronic hospital records for emergency room visits in Chicago to analyze how climate impacts health outcomes. The younger population were more likely to come in for external conditions while older individuals experienced health concerns like swelling, leg ulcers and kidney issues, said Peter Graffy, a postdoctoral fellow at the University of Chicago.Dr. Abel Kho, professor of medicine at Northwestern University’s Feinberg School of Medicine, said their data and research could be used to create climate adaptive healthcare, in which electronic records could pinpoint who is most at risk during a heat wave so that they could take preventative measures.“The ideal situation is you would see no spike at all during heat events because everyone knew it was coming,” said Kho, one of the study’s authors. “And they knew that they were at risk and they did the appropriate things, and it would look no different than any other day.”‘My brother’s keeper’Tanja Sopys said Chicago officers patrolling neighborhoods could do more to pass out water or check for people showing signs of heat stress. But she said the city also needs deeper investments for community mental health services.Tanja Sopys said her brother, who lived with mental health conditions, was never able to independently live on his own, transitioning from the care of their mother to their grandmother and then to her, the big sister. He bounced around different facilities, but he was never given a long-term solution, she said.“Everybody that dealt with my brother was so eager to put him out, let him go,” she said.Three months after her brother’s death, anxiety fills her whenever she drives near where he was found. Inside her living room, his black urn, decorated with his photo, is displayed on a bookshelf. She memorialized her brother in a video titled “my brother’s keeper,” showing photos of him at family gatherings.The two were overprotective of each other, she said. Whenever she felt down, David Sopys would sit next to her and that was enough to comfort her.“I keep seeing him walk down the street,” she said. “Somebody just walking, I keep thinking that he’s going to come and ring the doorbell. And if I see somebody that looks like him, it’s just still there.” ...read more read less