A recent Apple software update has given iPhone users a way to stay in touch even if they can't rely on the cellular network.Apple says iOS 18 supports iMessage and SMS messages sent via satellite, even when cellular service or wi-fi aren't available. This could help users stay in touch during natural disaster scenarios, which may damage or overwhelm cellular service.The feature is available on iOS version 18, running on the iPhone 14 or later. It is free for two years after activation of the phone.Connecting to satellite service requires being outside with a clear view of the sky and horizon. It is managed through the phone's Connection Assistant.Sending and receiving messages via satellite may take more time than you're used to.RELATED STORY | Hurricane Milton: Evacuation zones in Florida and what they meanApple says if you need to contact emergency services, you should rely on a separate feature called "Emergency SOS via satellite."This tool can quickly provide certain emergency info to responders where you are, the nature of your emergency, and prearranged medical info and your phone's remaining battery life. It can also notify emergency contacts that you've set up.The emergency feature only works via satellite connection. It isn't usable if you have a functional cellular or wifi connection.In the U.S., Emergency SOS is available on iPhone 14 models running iOS 16.1 or later.Google also offers an Emergency SOS feature on certain Pixel phones running Android 13 or later.RELATED STORY | What's it like leaving Florida ahead of Hurricane Milton?The combined high demand and potential for damage to infrastructure can make cell phone service uniquely fragile during natural disaster scenarios.In general, during an emergency, FEMA and the Federal Communications Commission recommend limiting cell phone calls to emergency services and relying on text messages for other communication, since texting places lower demand on the network.