An emergency alert will hit phones Wednesday. Here’s what to expect.

On Wednesday at 2:20 p.m. Eastern, most Americans will simultaneously feel their cellphones vibrate, hear them make a loud sound and see a push alert pop up on their screens. Most radio and television stations will broadcast an alert at the same time for about one minute.

There is no national emergency, no reason to panic and nothing you need to do about the alerts. It is, as the text will say, just a test.