Were the fleeing Engineers already infected? And if so why would they run TO the refrigerated chamber of Black Liquid, noting that this one chamber was more of a Temple (with the giant head) as opposed to the much more boring (and apparently un-refridgerated) cargo holds elsewhere in the movie? Was it that they felt the freezing temperature would stop the gestation of the Black Liquid in their systems? Or, were they fleeing to the refrigerated chamber because the door was the strongest to keep out the monsters chasing them?