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.