Your phone has 1% of battery left, and you are (trapped) inside a sealed environment with enough air to last you 1 day. What will you do?

 I’d whip out my iPhone 7 Plus and slam on the sleep button 5 times in rapid succession, then lay against the nearest wall as I watch my phone count down and contact emergency services, and my family. Hoping they can locate me as fast as possible.

 iPhone has an amazing feature called “Emergency SOS” 

 On up to dates version of iPhone, you can press the sleep button 5 times quickly to pull up an Emergency SOS page, where you can (by default) swipe to contact your local emergency services and send an alert text to all your emergency contacts with your location and time of alert. 

This feature has the potential to be life saving, and yet many people have yet to hear of it.