Even 20 years later, Dr. Patrick Angelo struggles to explain the freezing February night when he felt a command to get into his car and drive downtown to go feed and warm the homeless. He didn’t know his way around downtown Chicago. But after making some random turns, he arrived at a homeless encampment on Lower Wacker Drive, where he had never been before.

For about 13 years, Angelo spent four nights a week buying food with his own money and bringing it to about 70 people per night in their makeshift shelters in the bowels of the city. He kept up that schedule even while working his day job as a periodontist and developing a business called The Angelo Method. Recently patented, TAM helps people with diabetes and excess weight regain their health.