Senior Airman Julian Hernandez, a 28th Civil Engineer Squadron heating, ventilation and air conditioning journeyman, fixes wires that powers a fan at Ellsworth Air Force Base, S.D., May 3, 2018. The 28th CES HVAC shop is responsible for installing and maintaining all of Ellsworth’s heating, cooling, ventilation and refrigeration equipment. (U.S. Air Force photo by Airman 1st Class Thomas Karol)