The death of her older sister, who had wanted to become a doctor, spurred del Mundo to become a physician. Returning to the Philippines during World War II and volunteering for the International Red Cross, del Mundo cared for children of foreigners in an internment camp at the University of Santo Tomas, earning her the name “The Angel of Santo Tomas”. Frustrated by the scarcity of hospital beds while running a government-funded children’s hospital, she sold her home and possessions to build the first children’s hospital in the Philippines, the Children’s Medical Center in Quezon City. In a career spanning eighty years until her death a few months short of 100 years old, del Mundo brought healthcare services to rural regions of the Philippines. She invented an incubator made from bamboo to keep infants warm in villages lacking electrical power.
