Day-hike syndrome is the unfortunate (and sometimes deadly) result of over confidence combined with lack of preparation. People who go out on short hikes in familiar surrounds are most vulnerable, because they mistakenly believe that nothing can or will go wrong. So off they go, totally unprepared to spend the night in the wilderness or hunker down and wait out a sudden and unexpected storm.
All it takes is a twisted ankle or taking the wrong fork in the trail to turn a day hike into an overnighter — or even longer. It’s a very good idea to always be prepared with enough equipment to spend a few days on your own. At least carry a rudimentary shelter like the tube tent pictured above, so you can get in out of the rain and wind. Being alone and lost might scare you but it probably won't kill you. But hypothermia will, so always take enough gear to allow you to stay dry and conserve your body warmth.
To make sure you don’t have to spend too much time lost or alone, always leave a hike plan with trusted friends or loved ones, detailing where you’re going and when you’re planning to return. That way, if you don’t show up on schedule, someone will report you you missing and be able to supply search teams with your hike plan.
Better yet, carry a personal locator beacon or a SPOT satellite personal tracker, so you can immediately call the rescue squads yourself at the moment you find yourself in trouble.
Bottom line — day hikes sometimes last a lot longer than a day. Be prepared. Expect the unexpected.