Industries must increasingly take preventive measures to protect their workers against heat-related injury and illness during warm months when daily temperatures become hotter. To determine what protections should be used, they may follow guidelines from bodies of knowledgeable experts.
One such set of guidelines comes from the American Conference of Governmental Industrial Hygienists (ACGIH) - they recommend that industries employ the Threshold Limit Values (TLV) for work in hot environments. The ACGIH TLV consider both environmental conditions and work demands with the goal of maintaining the internal body temperatures of workers within safe limits. However, it is unclear if these guidelines adequately protect workers.
‘The American Conference of Governmental Industrial Hygienists do not adequately protect workers from potentially dangerous increases in their internal temperatures.’
In this study, investigators applied the ACGIH TLV recommendations for work-rest periods by having the study participants perform moderate intensity work bouts in progressively hotter environments. As environmental heat levels increased, the recovery periods between work bouts were lengthened. Yet, the core temperatures of the young physically active adults tested rose continuously.
These findings demonstrate that under the work conditions tested, the ACGIH TLV do not adequately protect workers from potentially dangerous increases in their internal temperatures. Therefore, current guidelines should be revised, especially given the warming climate and the increase in the frequency and intensity of extreme heat events.