Wilderness Medicine is a growing field of academic interest and clinical utility. It addresses prevention, assessment, and treatment of accidents and illness in environments featuring the extremes of heat, cold, altitude and depth, extended time to definitive care, and limited equipment. Improvisation, teamwork and critical thinking derived from a applied understanding of the physiology and pathophysiology of humans are highlighted and essential. Applications exist in expedition medicine, search and rescue, rural EMS work, mass and military casualty incidents, disaster response, remote occupations (i.e. ranching, resource extraction, public lands management) and personal recreation.