Under bridges, in alley ways, and on the streets of Pittsburgh, a team of doctors deliver house calls to those with no home.
Almost every night, Dr. Jim Withers, an internist and teaching physician at Mercy Hospital, can be found asking homeless men and women to read their blood pressure and offering to treat many illnesses that may have otherwise been overlooked.
"I think what it boils down to is that we're in this together," Withers said. "We are committed to each other in a way that hopefully nobody is ever completely outside the circle of caring."
He calls his mission Operation Safety Net (OSN) -- a nonprofit organization of doctors, nurses, and other medical experts who assemble in teams of three or four each night to offer food, clothing, and medical supplies to the city's homeless.
Among Withers' patients is Mark, 43, who has been homeless for a decade. He lives beside the train tracks under the Birmingham Bridge and suffers from bipolar disorder, arthritis, and diabetes. He's been drinking most nights since he was 13 years old, and admitted to Withers that he has neglected taking his medications.
"Well I haven't been taking my insulin and I haven't taken my inhaler," Mark said to Withers.
But Withers does not give up.
"I'm going to start you back on your insulin on a lower dose to be safe," Withers said. "We'll figure it out together."
As a teenager, Withers traveled with his father, a doctor, and his mother, a nurse, on medical missionaries across Central America. These missions paved Wither's path early, he said.
Nearly 20 years ago, Withers dressed like his homeless patients and took to the streets, even though he said he did not think he would be welcome. Although he was held at gunpoint three times, he continued to practice his so-called street medicine.
"I just felt like this was worth dying for," said Withers.
Today, most of the homeless community knows Withers. OSN operates under the umbrella of the Pittsburgh Mercy Health System, where Withers is a faculty member. Based on an cost-saving analysis done by OSN, Withers estimates that OSN has saved the state about $240,000 in emergency room costs by offering preventative services to the uninsured and homeless.
"The actual savings are undoubtedly higher when one considers the probably decreased re-admission rates avoided through street follow-up, the decreased length of stay related to our consult service and improved discharge planning as well as the preventive care and monitoring of the health of those still on the streets," Withers said.
Besides offering medical attention, Withers has helped more than 400 people get back on their feet and off the streets.
Lois, 60, is one example of Withers' success stories. Lois, who suffers from post-traumatic stress disorder, lived behind a garage near Withers' office.
"I had milk crates I used to sit on in the daytime," she said.
With the help of federal funding provided to OSN, Lois was able to move from the back of a garage to a furnished apartment.
Lois' story is one of the many reasons Withers says he continues his mission to save people's health and well-being.
"There's something about seeing someone come from a snow bank," Withers said. "I won't give up no matter what, to let her know that she mattered, that we were going to be there for her."