I clean mine with a damp sponge while it's still warm because it's much easier to clean that way. Also, use warm water one the first couple of wipes so you don't cool it down to fast.
Also, too much and too cold of water can shorten the life of the non-stick coating. My brother ran his under cold water (unplugged of course), and his non-stick coating lasted about 1/4 as long as mine. I haven't looked into it, but I suspect the hot plate material has a slightly different coefficient of thermal expansion than non-stick coating.
~Todd