Emergency sos is a feature in Apple's Health app that can be used to call emergency services. It is an important feature to know about as it can save lives in case of an accident or emergency.Using the feature is simple. Just press and hold the side button and one of the volume buttons together for five seconds, and the phone will automatically call emergency services. You can also activate the feature by clicking the home button five times.The service works only when you're outside of cellular or Wi-Fi coverage. It can't be used while you're in an airplane, or when you're on a boat.It also won't work if you have a Chinese or Hong Kong iPhone that doesn't support eSIM. lone worker alarm It's not clear why this is the case, but it could be a security measure.Another thing to consider is your contact's availability and phone reception when you send an SOS message. If they aren't able to receive the text messages, it can cause delays in emergency response.Activating the feature requires you to save at least one Emergency Contact in the Health app. These contacts can be added or edited by going to Settings > Emergency sos.You can also share your location, battery status, and when you start and end a phone call with these contacts. This information can be helpful if you're out of range of a GPS satellite.It's worth noting that you must have Google Maps permission enabled to use this feature. Otherwise, the location info you share with your contacts will be available in Google Maps all the time.