In the time of emergency, we can use a poncho as hammock. The poncho should be sturdy, robust and strong enough to hold your weight. If you can use US Army poncho, it will be great. It is already prepared for the purpose, completed with all the needed holes for the ropes. With a little imagination, you could set it up easily. In the cold and mild temperature regions, to protect body from elements, you should have a liner for your poncho. This liner usually comes with the poncho. It acts as a field sleeping bag when attached to the poncho. The setting is also as easy as the hammock making.