U.S. Air Force Senior Airman Denver Welch, 94th Fighter Generation Squadron crew chief, steps out of a vehicle wearing mission oriented protective posture 4 gear to shelter in a simulated bunker during an exercise at Joint Base Langley-Eustis, Virginia, Oct. 12, 2022. MOPP 4 is assumed when there is alarm red, which designates an attack is imminent or in progress and/or contamination is present or suspected to be present. (U.S. Air Force photo by Airman 1st Class Mikaela Smith)