As we all know sometimes you have to save your selves and some people need this kind of thing for daily life in third world country's,even in the U.S during natural disasters a temporary solution is needed.
Step 1: Step1
Step 2: Step2
I know this is simple not to needed in most cases but isnt it beter to be over exposed than unprepared.
This would also make an excelent science demo project for kids.