Master Sgt. Gary Fletcher, 167th Airlift Wing bioenvironmental engineering superintendent, checks a wet bulb globe thermometer outside of his office, Sep. 5, 2018, at the Martinsburg, W.Va. air base as part of the unit’s thermal injury prevention program. The thermometer reading of 92 F, warranted black flag conditions and recommendations for work to rest cycles for those working outside. The bioenvironmental engineering office monitors the temperature throughout the day when temperatures are expected to reach at least 85 degrees Fahrenheit. They announce green, yellow, red or black flag conditions through the desktop alert system. The base command post then relays flag conditions over the public address system and other work centers relay the flag conditions through their radio systems. (U.S. Air National Guard photo by Senior Master Sgt. Emily Beightol-Deyerle)