Sergeant Austen Clark, the hot zone controller for the Search and Extraction Platoon, helps one of his Marines fasten and secure his gas mask before completing the final exercise of the afternoon during Exercise Scarlet Response 2015 at Guardian Centers in Perry, Georgia, July 21. The hot zone is the area where an incident occurs. Clark makes sure he keeps accountability of everything that goes on when his Marines go in and search a building, such as their gear, if there are any casualties inside or if there are any further issues besides what they already know. - Sergeant Austen Clark, the hot zone controller for the Search and Extraction Platoon, helps one of his Marines fasten and secure his gas mask before completing the final exercise of the afternoon during Exercise Scarlet Response 2015 at Guardian Centers in Perry, Georgia, July 21. The hot zone is the area where an incident occurs. Clark makes sure he keeps accountability of everything that goes on when his Marines go in and search a building, such as their gear, if there are any casualties inside or if there are any further issues besides what they already know.