If you've never used a portaledge before, you might be terrified by the prospect of sleeping on a ledge hanging from the slide of a cliff. They may look a bit precarious, but don't be fooled! Portaledges are perfectly safe when used correctly. You should always wear your harness when on a portaledge, even inside your sleeping bag. That way, your harness will catch you in the unlikely event that you roll off the ledge in your sleep.