The message will have an audible tone, and the text will read, "THIS IS A TEST of the National Wireless Emergency Alert System".
A Presidential Alert will be received on every cell phone across the nation on Wednesday, Oct. 3 at 2:18 p.m. ET.
Emergency officials sending out an alert about a pending disaster need only issue one alert with the IPAWS technology.
The content of the message will also make it clear you've received the test message.
Rules outlined in a 2006 law states that the White House can issue a presidential alert only if the public were in peril, or during national emergencies.
THIS IS A TEST of the National Emergency Alert System. People will not receive notifications of President Trump's tweets, said Johnson.
Hoffenheim 1 Manchester City 2: Silva settles it late on
Raheem Sterling, after a lightning end-to-end break, and Aguero went close to putting City ahead as they piled on the pressure. Sergio Aguero is a doubt for City's trip to Hoffenheim after limping out of the weekend win over Brighton with a foot injury.
Cell phones across the country are set to light up with a message from the federal government at 2:18 p.m. on Wednesday.
The test was originally scheduled for September but was postponed as FEMA responded to Hurricane Florence. This will be the first presidential-level test and residents can not opt out. You also have to be within range of an active cell tower to receive the alert.
Three New Yorkers filed a federal lawsuit last week attempting to block the test, saying it violates free speech and is an unconstitutional seizure of electronic devices. "Does this mean I'm going to get whatever message President Trump wants to send out through this alert system now?'" Werner said.
"Everything is secured, password-protected and then authenticated or checked by two people before that message is sent", the official said.
The test is for a Presidential Alert, a type of Wireless Emergency Alert only used for major emergencies that affect the entire country.
You can click on the "Related Link" with this story to go directly to FEMA's website with additional information about what to expect.
The official said the system includes safeguards.