"Squares marked as Orange are considered to be 'Hellfire' Terrain. Hellfire terrain is treated as one elevation lower than surrounding terrain. Characters who begin their turn occupying a square of Hellfire terrain take 1 click of unavoidable damage, unless they possess either the 'Mystical' or 'Monster' keyword. Damage caused by Hellfire damage cannot result in a KO."
Pretty straight forward.
HCFL 2010 Champion , HCFL 2009 2nd Place
HCFL 2013 - Gotham Knights, FLE 2013 - The Intelligencia