VALFIS Research Group, Department of Physical Education and Sports, Institute of Biomedicine (IBIOMED), Universidad de León, León, Spain.
Front Public Health. 2024 Aug 7;12:1408591. doi: 10.3389/fpubh.2024.1408591. eCollection 2024.
Wildland firefighters (WFFs) regularly face demanding physical and environmental conditions during their duties, such as high ambient temperatures, challenging terrains, heavy equipment and protective gear. These conditions can strain thermoregulatory responses, leading to increased fatigue and posing risks to their health and safety. This study examined the effectiveness of two cooling interventions during physical activity in hot environments.
Eight active male WFFs participated, comparing the effects of wearing a cooling vest (VEST) and personal protective equipment removal (PASSIVE) against a control condition (PPE). Participants walked on a treadmill at a speed of 6 km·h for approximately 75-min under hot conditions (30°C and 30% relative humidity). Incremental slope increases were introduced every 15 min after the initial 20 min of activity, with 5-min passive recovery between each increment. Physiological and perceptual parameters were monitored throughout the protocol.
Significant main effects ( < 0.05) were observed in skin temperature (36.3 ± 0.2, 36.2 ± 0.4 and 35.4 ± 0.6°C in PPE, PASSIVE and VEST, respectively), physiological strain index (5.2 ± 0.4, 5.6 ± 1.1 and 4.3 ± 1.4 in PPE, PASSIVE and VEST) and thermal sensation (6.6 ± 0.6, 6.4 ± 0.7 and 5.3 ± 0.7 in PPE, PASSIVE, and VEST). However, no significant effects of the cooling strategies were observed on heart rate, gastrointestinal temperature or performance.
Despite the observed effects on physiological responses, neither cooling strategy effectively mitigated thermal strain in WFFs under the experimental conditions tested.
野外消防员（WFF）在执行任务时经常面临苛刻的身体和环境条件，例如高环境温度、挑战性地形、重型设备和防护装备。这些条件会使体温调节反应紧张，导致疲劳增加，并对他们的健康和安全构成风险。本研究检验了两种冷却干预措施在热环境中进行体力活动时的效果。
8 名活跃的男性 WFF 参与了研究，比较了穿冷却背心（VEST）和去除个人防护装备（PASSIVE）与对照条件（PPE）的效果。参与者在热环境（30°C 和 30%相对湿度）下以 6km·h 的速度在跑步机上行走约 75 分钟。在活动开始后的 20 分钟后，每隔 15 分钟引入递增坡度，每个递增坡度之间有 5 分钟的被动恢复。整个方案中监测生理和感知参数。
在皮肤温度（PPE、PASSIVE 和 VEST 分别为 36.3±0.2、36.2±0.4 和 35.4±0.6°C）、生理应激指数（PPE、PASSIVE 和 VEST 分别为 5.2±0.4、5.6±1.1 和 4.3±1.4）和热感觉（PPE、PASSIVE 和 VEST 分别为 6.6±0.6、6.4±0.7 和 5.3±0.7）方面观察到显著的主效应（<0.05）。然而，冷却策略对心率、胃肠道温度或表现没有显著影响。
尽管观察到对生理反应有影响，但在测试的实验条件下，两种冷却策略都不能有效减轻 WFF 的热应激。
