A surge in volunteers following a major disaster can overwhelm a response system, and without overall coordination, can actually make a situation worse instead of better. The outpouring of medical volunteers who responded to the devastating earthquake that rocked Haiti in January provides a roadmap for health care providers during future disasters, say the authors of a New England Journal of Medicine "Perspectives" piece that will be published online February 24. Thousands of doctors and nurses stepped up to help following the quake, but many were frustrated by difficulties connecting with a system that could immediately take advantage of their skills in the disaster zone. But lead author Raina Merchant, MD, an emergency physician and Robert Wood Johnson Foundation Clinical Scholar at the University of Pennsylvania School of Medicine, says that volunteers can enhance their effectiveness by preparing for a disaster before it occurs and thinking critically about their ability to respond.