Most of the film was shot on location in Iceland. The actors had to pretend they were in a very hot environment of over 100 degrees Fahrenheit despite the fact that they were actually filming in sub-zero temperatures. The weather was so taxing that cast members passing out was an everyday occurrence, and the cast and crew took friendly bets on who would pass out first (the bets were made to keep morale high).
Locke mentions that Aiken used to be a Spartan. Colonel Randall Aiken, formerly Randall-037, was a SPARTAN-II supersoldier during the Human-Covenant War. His time as a Spartan is briefly explored in the novel Halo: Ghosts of Onyx.