Those with an Apple iPhone 7 or older model can set off Emergency SOS by rapidly hitting the side button five times (three times in India). You still have to drag the slider to make the phone call to 911. On the Apple Watch, holding down the crown will set off an emergency call without requiring the user to drag a slider. This feature is available with iOS 11 and WatchOS 4.
While this is a good system in theory, in real life Apple iPhone and Apple Watch users have been accidentally triggering the feature. For example, an Apple Watch wearer by the name of Jason Rowley, who uses his timepiece for its sleep tracking ability, accidentally pushed down the crown button on the watch while he was sleeping. This set off the Emergency SOS service, and at 1 am Rowley was awakened by three cops who had entered his bedroom in response to his accidental 911 call. The cops told Mr. Rowley that they had experience responding to calls triggered when Emergency SOS was set off unintentionally on the Apple Watch.
Last month, we told you about an Apple repair shop that has been responsible for 20 false calls a day since October. The location repairs iPhone, iPad and Apple Watch units, and Apple acknowledged the problem at the time. If you are concerned about accidentally making an emergency call and finding yourself in the company of armed law enforcement, you can reduce the chance of an accidental 911 call by going to Settings > Emergency SOS to disable Autocall. This will add another slider that will have to be dragged before the Emergency SOS service is activated.