Lots of things to consider in an Emer Descent. Definately a two-person job. First of all the cause must be considered, e.g. depressurization - Masks, interphone, etc, +the the Pax O2 switch must be pushed to ensure masks in the back. Then there's the matter of navigation and blitzing through other people's airspace, AND how low to go. In the North Atlantic there are specific procedures for turning off course. Over parts of Greenland, there are altitude floors, lest you smite the rocks. One guy is going to be VERY busy flying, while the other monitors his performance and offers advice/direction on vector, altitude and warning on approaching parameters, as well as doing the checklists.