To my knowledge, there is nothing within the design intended to prevent obnoxiously low level characters taking legitimate risk exploring some stupid dangerous area.

Only things designed to

a) Prevent Joe the Hero from gaining exploration experience by exploring the kobold warrens.
b) Prevent random-Bob from using some "safety" hack like already being a ghost, duo dimension, projection (or any other random "You can't get killed" situation you can think of)

That's as far as I'm aware of level "ranges". You can never be too low, just too high.