STL Iterators

Do STL iterators need to be deleted when you're done with them? If I remember right, iterators are nothing but pointers that have been gussied up, but do they have their own destructors that clean up all their internal mess? I can't remember for the life of me and google is no help.

Pointers make it easy to step out of bounds, since their explicit size is not stored.
http://codepad.org/Szsb0qhF