Your iPhone can send an SOS to 911 and your loved ones if you’re in trouble. Here’s how

If you’re ever in trouble and don’t know the number to call for help, or you need to do so discretely, some cell phones are equipped with a feature that can connect you to emergency services and alert the people you’ve listed as emergency contacts — all without dialing a number.

iPhones with iOS 11 or later are equipped with a feature called Emergency SOS which, when activated, automatically connects you with the local emergency services number and sends a text message to people you have listed in your phone as emergency contacts that gives them your location at the time, according to the Apple website. Going a step further, the phone will send another text message to your emergency contacts when your location changes.

How you activate the feature depends on the model of iPhone you have, according to Apple.

On the iPhone 8 or later, press and hold the side button (the sleep/wake button) with one of the volume buttons until the “Emergency SOS” slider appears on the screen. Drag the slider to the right to call emergency services, or, continue holding the buttons and a countdown begins, during which an alert sounds and your iPhone automatically connects with emergency services.

On the iPhone 7 and earlier, rapidly press the side button five times, which will cause the “Emergency SOS” slider to appear, according to Apple. Drag the slider to call emergency services.

After the call ends, the iPhone sends everyone listed in your emergency contacts a text message that tells them you’re having an emergency and includes your current location, unless you choose to cancel it, according to the company. Even if you have location services turned off on the phone, it will turn on temporarily while Emergency SOS is activated.

To designate emergency contacts in your iPhone, open the Health app and add their contact information. You can also add information about health conditions, allergies, your blood type and even whether you’re an organ donor, in the event of an emergency during which you can’t relay that information to first responders.

For additional details about iPhone’s feature, including how it works on the Apple Watch, visit Apple’s website at support.apple.com.

Some Android devices are equipped with similar features, including some Samsung phones that can send a message to emergency contacts that you need help by tapping the power button three times. Samsung watches also work with the phone feature.

Manufacturers warn that these features should not be seen as a substitute for making a call to emergency services.

For phones that don’t include the SOS/emergency feature, there are personal-safety apps available for download.