on red alert

on red alert

At the ready to deal with or prepare for some imminent danger, threat, trouble, or difficulty. 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.

See also: alert, on, red

on ˌred aˈlert

prepared for an emergency or for something dangerous to happen: Following the bomb blast, local hospitals have been put on red alert.

See also: alert, on, red