Apple announced a lot of new features coming to iOS 18 at its WWDC 2024 event, but there wasn't time to cover everything – and additional upgrades continue to be revealed, including live video support for emergency SOS calls.
As described in Apple's press release for iOS 18, the new functionality is going to enable you to "share context through streaming video and recorded media". It means emergency dispatchers will have a better idea of what's happening and can provide help accordingly.
