7/10 Medieval ages I take it? Disease, blood, corpses, parasites. Might be safer up north where things are colder, or not. Have you tried using rain water?
"The East was a hard-fought campaign. Even now, I realize Caesar drew too much of the Legion's blood needed there for... this. Hoover Dam is but a place. I will not have it be the gravestone of the Legion - whether quickly, or as you describe, slowly... by attrition. As for wisdom... there is wisdom in your words, man of the West. If the West is one day filled with ones such as you, perhaps upon my return it shall be a worthy fight, indeed." Legate Lanius "The Monster of the East" from Fallout New Vegas.
This is some powerful character development and writing here. During much of the game, you're told that this Legate Lanius is a bloodthirsty animal who loves war but does not care for his own organization, The Legion, from both friend and foe. When you finally meet the guy, you realize Lanius does deserves his title of "The Monster of the East" but he's far from the mindless animal you heard of, that he's actually willing to listen to reason when his intellectual leader, Caesar, would not. I suppose it's a lesson that even if you think your opponent cannot be reasoned with, never take diplomacy off the table.