The emergency alerts are sent to devices that are within a specific geographic area. Most new devices already support the reception of Emergency Alerts and only need to be activated. Here are the devices that will receive the emergency alerts:

• Cellphones: All cellphones within range of an active cell tower should receive the national test. To receive emergency alerts, your phone must be connected to the mobile telephone network (4G/5G) and must be updated with required software. The Wireless Emergency Alerts (WEA) system has been used more than 84,000 times to warn the public about dangerous weather, missing children, and other critical situations – all through alerts on compatible cell phones and other mobile devices.

• Wireless devices: Wireless Emergency Alerts (WEAs) are free wireless notifications that are delivered to your mobile device as part of a new public safety system provided by Authorized Senders. Most new wireless devices already support the reception of Emergency Alerts and only need to be activated.

• Radios: The Emergency Alert System (EAS) for radios is being tested at the same time as the WEA system for phones. The alert sent on radios will last for 1 minute and will state: "This is a nationwide test of the Emergency Alert System, issued by the Federal Emergency Management Agency, covering the United States from 14:20 to 14:50 hours ET. This is only a test. No action is required by the public".

• TVs: The Emergency Alert System (EAS) for TVs is being tested at the same time as the WEA system for phones. The alert sent on TVs will last for 1 minute and will state: "This is a nationwide test of the Emergency Alert System, issued by the Federal Emergency Management Agency, covering the United States from 14:20 to 14:50 hours ET. This is only a test. No action is required by the public".

It is important to note that participating carriers may allow subscribers to block all but National Alerts.