Most Canadians should be prepared to hear an alert coming from their wireless devices, radio and TV stations but there is no need to be alarmed.
A country-wide test of the national public alert system is set to take place Wednesday afternoon.
Provincial and territorial emergency management systems will be sending out test signals to phones in every part of the country except Nunavut.
The alerts are used to warn of imminent threats or emergencies, such as floods, tornadoes, fires, or Amber Alerts.
Since January, the Canadian Radio-television and Telecommunications Commission (CRTC) says 125 emergency messages have been issued, warning Canadians of potentially life-threatening situations.
The emergency alerts have been credited with saving lives, according to the CRTC.
The test is expected to happen around 2:55 p.m. in Ontario.