Whenever Elizabeth Sheehan drives into Boston, she makes a mental note of how many shipping containers she spots near the harbor. “There’s a wall of them, and some haven’t moved in months,” says the Massachusetts resident. If Sheehan gets her way, many of these surplus metal boxes will soon be transformed into clean, efficient health care centers outfitted to serve the most vulnerable people throughout the Caribbean, Africa, and Southeast Asia. That’s the idea behind Containers to Clinics (C2C). Sheehan, a physician’s assistant with a decade of health care experience in the developing world, founded the nonprofit in hopes of “delivering lifesaving medicine and health care to the last mile.” She has seen what happens when there is no access to basic medical care. “The most vulnerable populations—rural women and children—die in droves,” she says, often from treatable illnesses like diarrhea and pneumonia. The prototype C2C design, developed in collaboration with sustainable building specialists and public health experts, combines two retrofitted containers in an “L” shape. One side contains private, well-lighted examination rooms and basic diagnostic equipment; the other houses a pharmacy and medical laboratory. Solar-powered fans keep the metal boxes from overheating, and a canopy offers shade for waiting…