Environmental medicine, as it relates to Canadian Armed Forces personnel, covers all phases of operations, in the air, on the ground, in ocean depths. D.C.I.E.M.'s purpose is to extend man's capabilities in whatever element he serves, at the same time providing life-support systems to ensure his safety. In aviation research, Arctic land exercises, submarine divers, and in the Institute's laboratories, this film shows many examples of D.C.I.E.M. developments.