Using iPhone as a simple emergency phone
With the “Assistive Access” mode, which is available from iOS version 17, the complete operation of the iPhone can be greatly reduced. Essential apps such as phone, messages and contacts can be displayed with large icons. This helps people with cognitive impairments.
An iPhone with “Assistive Access” enabled can also be used as an emergency phone for children. Of course, this requires that you have an iPhone that allows you to update to version 17.
Activate Assistive Access
“Assistive Access” is configured and activated in the settings under “Accessibility”.
You can specify which of the essential apps should be available and to what extent they can be used. In the phone settings, for example, you can specify which contacts can be called.
Deactivate Assistive Access
If you want to end “Assistive Access” mode, click the side button three times in succession.
Image source / official help article: support.apple.com