If an ear-piercing alert blares through your cellphone at 1:20 p.m. on Wednesday, don't panic.

The federal government will be conducting a nationwide test of its Emergency Alert System (EAS) and Wireless Emergency Alert (WEA) on Wednesday afternoon, sending messages through several communication channels, including cellphones.

There's no opting out. The purpose of the test is to ensure the effectiveness of the alert systems in reaching the public during emergencies — particularly those on the national level, according to the Federal Emergency Management Agency (FEMA), which is working with the Federal Communications Commission to conduct the test.

The scheduled day for the nationwide test coincides with the statewide tornado siren drill that echoes across Minnesota at 1 p.m. on the first Wednesday of each month.

But in Hennepin County, regular siren testing will occur at the same time as the nationwide alert. Conducting two separate drills might cause confusion and heightened anxiety among the public, county officials said in a release.

"This is a rare opportunity to mirror real-world scenarios where all warning tools are activated simultaneously, enhancing the value of the combined drills," said Eric Waage, Hennepin County's emergency management director.

Beginning at 1:20 p.m. Wednesday, the EAS portion of the test — scheduled to last for about 60 seconds — will send an emergency alert to radios and televisions, while the WEA portion of the test will be broadcast by cell towers for about half an hour.

The WEA test will be the third nationwide test, but the second test to be sent to consumer cellular devices. The free one-time message will appear in either English or Spanish, depending on the language settings on your phone.

The English message: "THIS IS A TEST of the National Wireless Emergency Alert System. No action is needed." Phones set to Spanish will display: "ESTA ES UNA PRUEBA del Sistema Nacional de Alerta de Emergencia. No se necesita acción."

To ensure accessibility for all, including people with disabilities, the alerts will be accompanied by a unique tone and vibration, according to federal officials.

In case of severe weather or other significant events, the test will be rescheduled for Oct. 11.