Large-diameter ceiling fan (LDCF) installed in a conditioned restaurant. Photograph courtesy of Big Ass Fans calculation to show the impact of air-circulating fans in terms of heat-index exposure. Occupant Heat Strain in Heated-andVentilated-Only Warehouses Heat stress is the result of increased heat load on a person's body. When heat load exceeds the body's ability to reject heat, the physiological response is referred to as heat 28 2022 AMCA inmot ion strain. Frequently, heat strain is contextualized in terms of heat index, which can be calculated based on the drybulb temperature and the moisture content of air, most often in terms of relative humidity. As Table 3 shows, heat index can be classifi ed according to heat-strain effects associated with exposure. Note that for the purposes of this study, " dangerous " levels of heat strain are conditions under which the heat index is above 90°F (32.2°C) www.amca.orghttp://www.amca.org