This is the proceedings of an international symposium arranged by the Swedish Delegation for Applied Medical Defense Research conducted in Stockholm Feb 5 to 6, 1965. The conference consisted of 50 contributors; 43 were from Sweden, 5 from the United States, 1 from Denmark, and 1 from Argentina. The papers were concerned with physiological reactions under conditions of emotional stress. Medical, industrial, and military implications were discussed. These are scholarly discussions with lively comment on papers, generous bibliographies, and no index.