be on red alert(redirected from are on red alert)
be on red alert
To be very attentive and ready to take action. This term is often applied to soldiers. We're safe here—the soldiers patrolling the border are on red alert. As soon as I heard my window break in the middle of the night, I was on red alert to fight off an intruder.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.