Prometheus was a Greek Titan. Possibly one of the most important Titans, as he stole fire from Zeus and gave it to the humans. This system was developed to resist those forces through technological means.
A small, primitive village has yet to discover fire, which is a good thing because there are highly flammable (but not otherwise dangerous) gasses in the air. The heroes, blissful in their ignorance, don't know that and think it a wonderful idea to show the locals open flame.