Any specific tips on communicating "danger" to a spirited 19 month old?

Our little lady doesn't listen at all ... It's literally like she can't hear (she can) when we are outside of the house. I totally understand and respect that she's outside, and it's amazing, but I need to find a way to ensure she's listening to me.

Things like: walking right towards a ledge, a hot grill, the street, etc. Obviously, my goal is that I always hold her hand, or can be there to intervene quickly, but when can I realistically expect her to listen??

This morning, I put her down to load bags into the car, and she immediately started walking towards the street. I told her, "Stop!" ... "Can you please turn around?" ... "That's dangerous!", before I had to run over to grab her. She doesn't bat an eye.

Girlfriend can understand "Can you please go to your room, get your jammies, and put them on?", so I know she knows how to "stop" ... She's just sooo not into listening.

Help!!