In 1943 Sievers became director of the Institut für Wehrwissenschaftliche Zweckforschung (Institute for Military Scientific Research), which conducted extensive experiments using human subjects.
1943 yılında Sievers, Institut für Wehrwissenschaftliche Zweckforschung'un (Askeri Bilimsel Araştırma Enstitüsü) müdürü oldu ve insan denekleri kullanarak kapsamlı deneyler yaptı.