This is a test. This is only a test. But get ready for it anyway.
On Wednesday, the whole nation will be put on alert. But don't panic - it's only a test.
At 2:20 P.M. Eastern Time, warning alarms will sound on all cell phones, TVs, and radios across the United States.
It's all part of a nationwide emergency alert test.
Wednesday's alarm will be followed by the message: "This is a test of the National Wireless Emergency Alert System. No action is needed."
Tests like this are done every three years to ensure all systems are working properly.