"In the fall of 1916, before the United States entered World War I, the National Research Council named Cannon a member of a committee on traumatic shock. Later he joined the Harvard University Hospital Unit. On his way to France in May 1917, he stopped in London and arranged with Fletcher, first secretary of the Medical Research Committee, to join the group of physicians and surgeons of the British Expeditionary Forces who were dealing with shock cases at the Casualty Clearing Station at Béthune. . . . Initially Cannon and his associates in the field concentrated their therapeutic efforts on treating the acidosis that accompanies shock. Later they recognized that the acidosis was merely a secondary phenomenon, the result of the inadequacy of tissue perfusion. In 1923 Cannon summarized his wartime experience in Traumatic Shock" (Dictionary of Scientific Biography).