The priorities for sustaining life--air, shelter, water, and food--are the subjects of this module designed to give junior and senior high school students the foundation for safe, rewarding experiences in the outdoors. Five 50-minute lesson plans cover the basic need in order of priority: air (3 minutes to survive without it), shelter (3 hours, in extreme conditions), water (3 days), and food (3 weeks). The module contains background information for teachers, outlines for class lectures, lists of materials for each lesson, and learning activities for students. The first lesson provides an overview of outdoor recreation and the ethics of protecting the environment as well as information on the need for air. Two lessons on shelter discuss ways to avoid hypothermia and hyperthermia and outline the effects on body temperature of radiation, convection, evaporation, respiration, and conduction. The lesson on water covers dehydration, control of water loss, and water purification; students try five methods of purifying water. The lesson on food stresses planning caloric intake for outdoor activities. Some information is specific to outdoor conditions in Missouri; a directory of resource people in Missouri's outdoor skills and conservation education programs is provided. A glossary, a wind chill chart, clothing lists, and a bibliography are included. (JH)