Don’t be alarmed when your phone buzzes incessantly with an emergency alert from the president today (Wednesday) — it’s only a test. But unlike the emergency alerts and AMBER alerts that you can toggle off on your smartphone, you won’t be able to switch off the notification for this “presidential alert,” which is designed to be used “in the event of a national emergency,” according to FEMA (Federal Emergency Management Agency).

The test should fire at about 1:18pm Chicago time!