U.S Air Force Airman 1st Class Dannyel Butte, 325th Aerospace Medicine Squadron bioenvironmental engineer apprentice, assists Airman 1st Class Dorothy Russell, 325th Aerospace Medicine Squadron bioenvironmental engineer apprentice, with her gas mask fit test at the 325th Medical Group Clinic on Tyndall Air Force Base, Fla., Jan. 25, 2017. Bioenvironmental engineers help protect Airmen and their families from environmental and occupation hazards, preventing and controlling the spread of disease, and safeguarding the physical and mental wellbeing patients. (U.S. Air Force photo by Senior Airman Dustin Mullen/Released)