To put it simply. If you click move the guy will ALWAYS walk into the fire or any hazards it can.
Its getting so frigging annoying having to move characters 1 square at a time, because as soon as i forget to do that, I have to go and reload cause they just walked into the fire.

And yeah the routing seems to purposely have them walk into the fire, as i wanted someone to move 3 squares up then one to the side, and he ALWAYS walked 1 square up, 1 to the side into the fire.
And if the fire was 3 squares ahead, he will always walk straight ahead and never go to the side first.