Authorities on Monday released the cause of death for the patient who died hours after she was found on the roof of Vista Medical Center East in Waukegan.
An autopsy determined Chelsea Adolphus, 28, of Waukegan, died from hypothermia as a result of cold exposure, according to the Lake County Coroner's Office. Adolphus was admitted to the hospital at around 4 a.m. Wednesday morning for unspecified medical issues. She was found unresponsive on the roof of the hospital at around 8:45 a.m. on Thursday, and was only wearing a hospital gown at the time.
Adolphus was subsequently taken to the hospital's emergency department, where her body temperature was determined to be around 55 degrees, the coroner stated. She was pronounced dead roughly 14 hours later - at 11:03 p.m. According to the coroner's office, the 28-year-old was determined to be missing from her room around six hours before she was found.

As a result of the "unusual circumstances" surrounding the incident, Waukegan police launched an investigation into what occurred. It remained unclear how Adolphus gained access to the rooftop as of Monday.
"We want to know exactly what happened from when my sister stepped foot in that facility," said Tiffany Adolphus' brother, Paul Adolphus. "If anyone or staff knows anything... me and my family ask you come forward... for justice for my sister."
At a press conference, Lake County Coroner Jennifer Banek explained she previously voiced concerns about what she calls a lack of care and safety measures at the facility.
Local
In February of 2024, Vista Medical Center East had its designation as a trauma center revoked by state officials for not having appropriate blood supply and clinical staff available for patients, she stated.
Banek said, most recently, the hospital furloughed 69 employees, including sitters - staff members who sit and monitor patients when they are most vulnerable.
Feeling out of the loop? We'll catch you up on the Chicago news you need to know. Sign up for the weekly Chicago Catch-Up newsletter.
"Accidental loss of life because of lack of appropriate basic safety measures cannot happen again," she stated. "More delays and excuses puts Vista patients at risk. It is past time for all stakeholders to step up and find solutions that ensure safe, quality health care at Vista Medical Center."
NBC Chicago reached out to the parent company of Vista Health System, but had yet to hear back as of Monday afternoon.