If you have an iPhone, don't go anywhere you shouldn't be without doing the following:
Settings/Privacy/Location Services... OFF
That turns off the GPS and NOTHING can see where you are.
Sure, you won't be able to use Maps, or anything find out what the Weather is like in your area, but the peace of mind outweights the metereological foresight. Then when you're home, turn it back on.
If you're questioned, say the battery ran out, or you were stuck in a tube tunnel, or that a small nuclear explosion occured close to where you live...