Being able to call for help in an emergency is a great feature. However, an automatic calls means it is sometimes used accidentally. Just this week I was sitting at the table working on a jigsaw puzzle when my iPhone, resting in my pocket, called two of my emergency contacts! Luckily, I had turned off Auto Call so that it didn’t dial 911.
So it’s useful to know how this feature operates , and how to configure it to work on your iPhone. In the Settings app, scroll down to Emergency SOS and tap on it. Toggle the Auto Call button on or off. If you turn it off (gray means off), you can still call 911 by sliding the SOS button (shown in the screen-shot on the right) left to right yourself — it just won’t happen on its own.
You may also be able to trigger an emergency call by rapidly pressing the side button 5 times. If so, you can disable this feature on the same page of the Settings app.
If you’d like more details — including screen shots — this article in iMore gives details of how to set it up Emergency SOS, change the configuration, and use it on various versions of the iPhone and the Apple Watch.
This article by Apple also gives an official description of the features, along with links to related articles.