heat from exhsast is this normal

Hi i have just bought a 1999SE Range Rover and in the process of renewing the head gaskets so far so good apart from the rear head bolt that rounded but I eventuly removed
my question is I noticed that the left hand plastic shock cover is all melted would this be from the manifold as there was no heat sheild instaled
the other side is the same no heat sheild should i be concerned.
RRDAFT

its usually a leak of hot gasses that causes the problems, mine (and many more i suspect) dont have the heat shield and is fine, no burns or anything!