Apple released its most recent operating system, iOS 11, earlier this year.

It introduced a number of new features for iPhones and iPads, including an improved messaging app, a smarter Siri and augmented reality. The tech giant's latest update also brought in the new Emergency SOS feature, which allows people to ring emergency services in a  discreet way. You can also assign Emergency Contacts, who will get a notification after you've rang emergency services. Twitter user Alfred Samuel pointed out the Emergency SOS option when going through his phone's settings after downloading iOS 11. He posted some screenshots as well, explaining exactly what it does. https://twitter.com/RealASamuel/status/912013860076433408 He added:

"If you are in danger there is a new feature, press the lock button 5 times in a row it gives a 3 second countdown and rings the police."

People who own an iPhone 7 or any earlier model are advised to "rapidly click the sleep/wake button five times to quickly call emergency services". But if you've got an iPhone 8, 8 Plus or X, you can activate the feature by pressing and holding down the side button alongside  one of the volume buttons until you  see the Emergency SOS slider. According to Cosmopolitan, if you see the slide button appear on the screen, emergency services will be phoned; however, if you don't, a countdown will start and a loud alarm ill begin at the end of it. The Emergency SOS feature lets you set up some emergency contacts, who will be contacted as soon as your call to emergency services ends. You can manage your emergency contacts by editing your Medical  ID in the Health app on iPhone. The description reads:

"When you use Emergency SOS, your device will attempt to call the emergency services. "To allow the call handler to assist you, this call may include your location, regardless of whether you enable Location Services. "Once the call ends, you can choose to notify your emergency contacts with a message that says you have called emergency services."

If you've got the location services switched off, Emergency SOS will temporarily turn it on. Your iPhone will also send updates to your emergency contacts if your location changes.