Yeah it is easy to miss them I got surprised multiple times when I was playing the first game.
If you mouse over the surface it will tell you can be frozen, electrified etc, giving you some hints but this is still not very clear.
And one thing is annoying actually is the pathfinding around those surface IN combat. I wish we could ask the game to use its pathfinding to go around because if you do it manually many times you step on places you did not suspect would burn/electrify/slow you etc.
