Career
He is a two-time Olympian (2000 and 2004), and served twice as Cambodia"s flag bearer in the opening ceremony. He also held a Cambodian record of 26.48 in the 50 m freestyle from the Southeast Asian Games. Hem is currently working as a swimming coach for the Cambodia national team.He is Danya"s and Sovann"s coach.
Hem made his official debut at the 2000 Summer Olympics in Sydney, where he competed in the men"s 50 m freestyle.
At the 2004 Summer Olympics in Athens, Hem swam for the second time in the 50 m freestyle. As part of an Olympic Solidarity program, he received a Universality place from FINA in an entry time of 27.56.
He challenged seven other swimmers in heat three, including 16-year-old Chris Hackel of Mauritius. He edged out Libya"s Khaled Ghezzawi to take another fifth spot by six hundredths of a second in 27.49.
Hem failed to advance into the semifinals, as he placed seventieth overall out of 86 swimmers in the preliminaries.
He is a son of Hem Thon (1943–2015), who was also a swimmer.