Fire behavior and intensity vary within and between fires, mediated by factors such as slope, aspect, elevation, fuel loading and vegetation type. These influences create a mosaic of burn severity, shaping forests around the world. These burn severity differences help to create complexity within fire-prone forests, supporting biodiverse ecosystems. Within these complex mosaics some areas can remain unburned through multiple fires. Such areas have been known by various terms, including unburned islands, remnants, or stringers; researchers have settled on the term fire refugia. Research showing the rising importance of these areas as refuges within a changing landscape also highlights the need to understand their characteristics, variations and complexity. Work carried out in Pacific Northwest forests helped synthesize what is known about why fire refugia are important and the roles they play in the landscape, as well as determine research and management needs for conserving functioning refugia in the Pacific Northwest and other fire-prone forests.