From 1911 to 1913, he performed military service with the Imperial German Army in the 133rd (9th Royal Saxon) Infantry Regiment, headquartered in Zwickau.

[1] Upon the outbreak of the First World War, Hess rejoined the army as a one-year volunteer and was assigned to the 134th (10th Royal Saxon) Infantry Regiment, headquartered in Plauen.

He became a non-commissioned officer, attaining the rank of Vizefeldwebel, and was awarded the Iron Cross, second class.

[2] Hess first joined the Nazi Party (membership number 6,840) at the Plauen Ortsgruppe (local group) in March 1923.

[3] Hess rejoined the Party on 2 June 1925, after the lifting of the ban, and also resumed his SA leadership post in Plauen.

Hess left his field command when he was appointed to a staff position as an SA-Führer for Special Assignments in OSAF on 15 January 1935, holding this post until the fall of the Nazi regime in May 1945.

On 14 May 1935, Hess was named the chief of liaison between OSAF and the Reich Artisan Master, Wilhelm Georg Schmidt [de].

He was named a Wehrwirtschaftsführer (military economic leader) on 7 February 1939 and, in May 1940, he was also granted a five-year appointment as a lay judge and assessor at the People's Court.