“ 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.”
“ A known immortal traveling with the PCs kills an attacker, and is arrested and charged with murder, since immortals cannot kill in self defense, being immortal.”
“ Able to raise body heat by concentration to save themselves in winter. Even to the point of drying freezing wet clothes.”