This weekend, the British government is trialling a system that aims to warn the public if there is a danger to life nearby.
Here's what's happening...
What is going to happen?
Millions of mobile phones and tablets across the UK will emit a loud alarm and vibrate at 3pm on Sunday in a nationwide test of the new public alert system.
The message will be received on 4G and 5G mobile phones, along with sound and vibration for up to 10 seconds.
The alarm will sound even if the device is set on silent.
British officials warned that some people in areas near the Border may also receive the alert.
Do people need to do anything?
Phone users will be prompted to acknowledge the alert by swiping or clicking the message before being able to continue using their device.
What is the purpose of this system?
The system, which is modelled on similar schemes in the US, Canada, the Netherlands and Japan, is intended to be used in life-threatening situations including flooding and wildfires.
Who sends the alerts?
Emergency alerts will only be sent by the emergency services or British government departments, agencies and public bodies that deal with emergencies in the UK.
Does a phone's location services need to be on to receive alerts?
The British government said people in the UK will get alerts based on their current location – not where they live or work, and location services do not need to be on to receive alerts.
What if the alert comes through when someone is driving?
The British government is urging people to not read or respond to an emergency alert while driving or riding.
People are advised to find somewhere safe and legal to stop before reading the message, and if there is nowhere safe and legal to stop, and nobody else is in the vehicle to read the alert, drivers can listen to news on live radio to find out about the emergency.
The AA said motorists may prefer to switch off their electronic devices before Sunday’s test as laws banning the use of handheld phones will still apply.
Can people opt out of the alerts?
Officials stressed that it is easy to opt out of the system if people need their phone to stay concealed, either by turning off the alerts or simply having the phone switched off during the test.
