But don’t worry, the president hasn’t gone mad and launched a nuclear missile strike. The Federal Emergency Management Agency is simply conducting a nationwide test of its Wireless Emergency Alerts (WEA) system, reports USAToday . The WEA is essentially the cellular device version of the Emergency Alert System (EAS) that is broadcast to radios and TVs.

In a statement alerting people to the test, FEMA said, “The purpose of the test is to ensure that EAS and WEA are both effective means of warning the public about emergencies, particularly those on the national level.” So at 2:18 p.m. if you have your cell phone turned on and you are within range of an active cell tower, and your wireless provider participates in the WEA system, you’ll receive the following message:

Presidential Alert: THIS IS A TEST of the National Wireless Emergency Alert System. No action is needed.

The message will appear only once and once you receive it you can safely dismiss it–this time. Future WEA alerts will be for real, however. They can be issued for anything from missing children to hazardous weather, or even allow the president a new way to address the nation during a national emergency.