Col. Patrick Tiernan, Deputy Group Commander, Marine Aircraft Group 41, 4th Marine Aircraft Wing, explains the importance of Chemical, Biological, Radiological, and Nuclear (CBRN) individual safety measures during Arctic Care 2021, Kodiak, Alaska, on May 7, 2021. Arctic Care 2021 is a joint-service training mission led by the United States Air Force and supported by members of the Air National Guard, Marines, Marine Reserves, Navy, Navy Reserves, National Guard, and Army Reserves. (U.S. Marine Corps photo by Lance Cpl. James Stanfield)