Simulated firefighting task performance and physiology under very hot conditions

PURPOSE: To assess the impact of very hot (45°C) conditions on the performance of, and physiological responses to, a simulated firefighting manual-handling task compared to the same work in a temperate environment (18°C). METHODS: Ten male volunteer firefighters performed a 3-h protocol in both 18°C (CON) and 45°C (VH). Participants intermittently performed 12 × 1-min bouts of raking, 6 × 8-min bouts of low-intensity stepping, and 6 × 20-min rest periods. The area cleared during the raking task determined work performance. Core temperature, skin temperature, and heart rate were measured continuously. Participants also periodically rated their perceived exertion (RPE) and thermal sensation. Firefighters consumed water ad libitum. Urine specific gravity (USG) and changes in body mass determined hydration status. RESULTS: Firefighters raked 19% less debris during the VH condition. Core and skin temperature were 0.99 ± 0.20 and 5.45 ± 0.53°C higher, respectively, during the VH trial, and heart rate was 14-36 beats.min(-1) higher in the VH trial. Firefighters consumed 2950 ± 1034 mL of water in the VH condition, compared to 1290 ± 525 in the CON trial. Sweat losses were higher in the VH (1886 ± 474 mL) compared to the CON trial (462 ± 392 mL), though both groups were hydrated upon protocol completion (USG < 1.020). Participants' average RPE was higher in the VH (15.6 ± 0.9) compared to the CON trial (12.6 ± 0.9). Similarly, the firefighers' thermal sensation scores were significantly higher in the VH (6.4 ± 0.5) compared to the CON trial (4.4 ± 0.4). CONCLUSIONS: Despite the decreased work output and aggressive fluid replacement observed in the VH trial, firefighters' experienced increases in thermal stress, and exertion. Fire agencies should prioritize the health and safety of fire personnel in very hot temperatures, and consider the impact of reduced productivity on fire suppression efforts.

Safety communication patterns in small work groups – a pilot study using social network analysis

As a project based industry, construction is portrayed through the short term and transitory nature of the industry. This is one of the factors that have been correlated to the poor safety performance of the construction industry. An essential part of safety performance, however, is the effective safety communication between all parties on construction projects. The construction industry is highly regulated due to its high incidence of work-place accidents. This is especially true of smaller building companies/enterprises where the burden of compliance to safety regulations is most onerous. The majority of current research in this topic area has focused on identifying the high risk components or the causes of increased risks. The literature on safety communication network patterns and its relation to safety performance is nevertheless minimal. Thus, this study takes the opportunity to explore the safety communication issue by analyzing the communications patterns in small workgroups. In a pilot study, through surveys with construction crews that are contributing to active construction projects in Sydney, Australia, patterns of safety communications were identified using social network analysis (SNA). The findings, though preliminary, has identified safety communication network patterns under formal communications and toolbox talks may determine a small group’s safety performance.