Nugiseks was born in Vanaõu farmstead, Karjaküla village, Särevere Parish, Järva County, Estonia. In 1943, he voluntarily joined the Estonian Legion. He received the Knight's Cross of the Iron Cross for leading the capture of the Vaasa-Siivertsi-Vepsküla bridgehead. As the I Battalion, Waffen-Grenadier Regiment der SS 46 lost almost all of its officers, Nugiseks stepped in as the leader of the attack. He immediately changed tactics, loading the supply of hand grenade onto sledges so the attackers would not have to crawl back for the supplies over the mine field. With the hand grenades being passed on along the trenches, the bridgehead was squeezed in from the north by the "rolling" tactics.
Nugiseks was mentioned in the Wehrmachtbericht and in the magazine Signal following his Knight's Cross award, which was personally given to him by the SA occupation head in Estonia, Karl-Siegmund Litzmann, while Nugiseks was in hospital. It was filmed.
Afterwards Nugiseks was demoted for fighting with some soldiers who were harassing Red Cross nurses. During the Soviet assault on Estonia in September 1944, Nugiseks's home was destroyed. Nugiseks was captured by Czech partisans in May 1945 and put in a POW camp. After three unsuccessful escape attempts, Nugiseks served time after being handed over to the Soviets, who sentenced him to 10 years in the Gulag and 5 years deportation in Siberia. Nugiseks managed to return to Estonia, where he worked until retirement.
In the 1970s, Nugiseks constructed a house for his family with his own hands. In 1992, as a result of his service to his country, Nugiseks was made a Captain of the Estonian Army. Nugiseks attended another Estonian Knight's Cross of the Iron Cross holder, Alfons Rebane's reburial in Estonia in 1999 by the Estonian government. In October 2008, he was awarded the Medal of Gratitude by the Estonian people, after collecting of 4229 signatures.
^(Estonian) Leo Tammiksaar (2001). Lühike ülevaade mõningatest Eesti üksustest Wehrmachtis, politseis ja SS-is. (A Brief Overview on some Estonian Units in Wehrmacht, Police, and SS. In Estonian). Lennuliiklusteeninduse AS, Tallinn
Fellgiebel, Walther-Peer (2000) . Die Träger des Ritterkreuzes des Eisernen Kreuzes 1939–1945 — Die Inhaber der höchsten Auszeichnung des Zweiten Weltkrieges aller Wehrmachtteile [The Bearers of the Knight's Cross of the Iron Cross 1939–1945 — The Owners of the Highest Award of the Second World War of all Wehrmacht Branches] (in German). Friedberg, Germany: Podzun-Pallas. ISBN978-3-7909-0284-6.
Scherzer, Veit (2007). Die Ritterkreuzträger 1939–1945 Die Inhaber des Ritterkreuzes des Eisernen Kreuzes 1939 von Heer, Luftwaffe, Kriegsmarine, Waffen-SS, Volkssturm sowie mit Deutschland verbündeter Streitkräfte nach den Unterlagen des Bundesarchives [The Knight's Cross Bearers 1939–1945 The Holders of the Knight's Cross of the Iron Cross 1939 by Army, Air Force, Navy, Waffen-SS, Volkssturm and Allied Forces with Germany According to the Documents of the Federal Archives] (in German). Jena, Germany: Scherzers Miltaer-Verlag. ISBN978-3-938845-17-2.