Born in Dessau, East Germany,[5] Hempel was a goalkeeper in handball, beginning his career with SG Kühnau,[6] before moving to Dessau-Roßlauer HV in the 2010–11 2.

[6] In 2016, Hempel ended his handball career in Cologne with Longericher Sport Club [de],[9] where he had moved to advance his educational studies;[6] he eventually qualified as a fitness coach and nutritionist.

[15] In April, he completed his first nine-dart finish during a European Super League whitewash victory over Marco Obst.

[16] Hempel made his PDC televised debut in October at the 2021 European Championship, eliminating reigning champion Peter Wright 6–3.

[5] During the 2022 PDC World Darts Championship, Hempel caused a "major upset" when he defeated fifth seed Dimitri Van den Bergh in the second round, averaging 98.37,[10] and described it as "madness".