If you find yourself in a situation where calling 911 could place you at greater risk, or you're unable to speak, your iphone has a little known feature that could save your life. You can call 911 without dialing. Simply press the lock button 5 times quickly. A screen similar to the above photo will appear. If you've set your medical ID, that will display on the screen along with the SOS option. If you're incapacitated when first responders arrive, the medical ID will alert them to any allergies, and inform them of what medications you may be on. You can also enter emergency contact information in your medical ID.