be on full alert

be on full 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 full alert. As soon as I heard my window break in the middle of the night, I was on full alert to fight off an intruder.
See also: alert, full, on
References in periodicals archive ?
The Philippine National Police (PNP) will be on full alert status on Thursday to prepare for the possible effects of super typhoon 'Mangkhut,' (local name 'Ompong') Police Chief Director General Oscar Albayalde said.
Regional and provincial mobile forces and other departments of the PNP will also be on full alert status, Albayalde said.