This volume is a report of a conference held under the auspices of the Josiah Macy, Jr., Foundation. The purpose of the conferences sponsored by this foundation is to bring scientific workers in various fields together so that they may present their observations and views on a subject. The attendance is limited to 25. The epidemiology of cold injury, resistance to cold, and pathophysiology of cold injuries are considered. It appears from the discussions that frostbite still remains an injury without a readily available form of therapy.