They are semi-permanent. You can buy (with the appropriate building) or find Iru's Elixer. This will heal your champion as well as remove a random injury they may have.
End of SpankTheMonkey's quote
Damn, I am playing my first game (have been playing it for a while, though) and I have basically treated many of my heroes as cannod fodder because I believed that they would basically just respawn at no cost other then having to wait for them to respawn.
Do heroes obtain these injuries and penalties only as a result of being defeated in a battle or can it happen simply by losing a lot of health in battle?
Also, I have noticed that if a hero is defeated in a battle but the army it is in wins then the hero won't actually be removed for a time like usual but is instead simply very wounded, When that happens can it still obtain injury traits?