On Dungeons: Planar Materials

In my game my world (originally) was a fourth dimensional bleedthrough of the four elemental planes. My history tied into that, where great genasi empires ruled at the formation of the world. Now it looks like a generic fantasy world.

The Four Elements are extremely pure, and so are their respective planes of existence - they react to our bodies like any chemical might.

Water causes instant Oedema. Earh would suck all the water out of your tissue. Elemental fire burns irreparably. Air would explode your lungs. Chaos would instantly force your molecules to their maximum state of entropy. They're vicious

As for the elemental plane of Law, see below...