This is how it works. You carefully select some survival items, put them into a bucket or any conatainer that can be sealed shut, and bury it somewhere hidden from other eyes.

In emergency , you may retrieve it or use it where it is to make shelter. It is good if you are caught unprepered or only have your humble PSK. However, I when I skimmed through th eother thread about shelter or the hills, I can see that a cache can help there too. You hide your things, and go to the shleter. Nothing on you that deserves to be confiscated or looted. If you deicde later to go on your own, or the shelter is no more hospitable for some reason, you head to your secret location, retrive the cache and try the hills.