Extending work tolerance time in the heat in protective ensembles with pre- and per-cooling methods

Investigate whether a range of cooling methods can extend tolerance time and/or reduce physiological strain in those working in the heat dressed in a Class 2 chemical, biological, radiological, nuclear (CBRN) protective ensemble. Eight males wore a Class 2 CBRN ensemble and walked for a maximum of 120 min at 35 °C, 50% relative humidity. In a randomised order, participants completed the trial with no cooling and four cooling protocols: 1) ice-based cooling vest (IV), 2) a non-ice-based cooling vest (PCM), 3) ice slushy consumed before work, combined with IV (SLIV) and 4) a portable battery-operated water-perfused suit (WPS). Mean with 95% confidence intervals are presented. Tolerance time was extended in PCM (46 [36, 56] min, P = 0.018), SLIV (56 [46, 67] min, P