 Hederén was a teacher at the Swedish Infantry Combat School from 1936 to 1939 and attended the Royal Swedish Army Staff College from 1940 to 1942 and was again a teacher at the Infantry Combat School from 1942 to 1946.He became major in the staff of the I Military Area in 1949 and served in the British Army in 1951 and in 1952.Hederén served in the Jämtland Ranger Regiment (I 5) in 1953 and was promoted to lieutenant colonel there in 1957.