title: The impact of different cooling modalities on the physiological responses in firefighters during strenuous work performed in high environmental temperatures.
abstract: This study investigated the impact of ice vests and hand/forearm immersion on accelerating the physiological recovery between two bouts of strenuous exercise in the heat [mean (SD), 49.1(1.3)°C, RH 12 (1)]. On four occasions, eight firefighters completed two 20-min bouts of treadmill walking (5 km h, 7.5% gradient) while wearing standard firefighter protective clothing. Each bout was separated by a 15-min recovery period, during which one of four conditions were administered: ice vest (VEST), hand/forearm immersion (W), ice vest combined with hand/forearm immersion (VEST + W) and control (CON). Core temperature was significantly lower at the end of the recovery period in the VEST + W (37.97 ± 0.23°C) and W (37.96 ± 0.19°C) compared with the VEST (38.21 ± 0.12°C) and CON (38.29 ± 0.25°C) conditions and remained consistently lower throughout the second bout of exercise. Heart rate responses during the recovery period and bout 2 were similar between the VEST + W and W conditions which were significantly lower compared with the VEST and CON which did not differ from each other. Mean skin temperature was significantly lower at the start of bout 2 in the cooling conditions compared with CON; these differences reduced as exercise progressed. These findings demonstrate that hand/forearm immersion (~19°C) is more effective than ice vests in reducing the physiological strain when firefighters re-enter structural fires after short rest periods. Combining ice vests with hand/forearm immersion provides no additional benefit.
authors.affiliation: Research Institute for Sports and Exercise Sciences, Liverpool John Moores University, Tom Reilly Building, Byrom Street Campus, Liverpool, L3 3AF, UK. spsdbarr@hotmail.co.uk
authors.forename: David
authors.initials: D
authors.lastname: Barr
authors.forename: Thomas
authors.initials: T
authors.lastname: Reilly
authors.forename: Warren
authors.initials: W
authors.lastname: Gregson
mesh_terms: D000328:Adult; D001833:Body Temperature Regulation / Q000502:physiology*; D003080:Cold Temperature; D004777:Environment; D005390:Fires; D006358:Hot Temperature / Q000009:adverse effects; D006801:Humans; D007036:Hypothermia, Induced / Q000379:methods*; D007101:Immersion / Q000503:physiopathology; D008875:Middle Aged; D016273:Occupational Exposure; D009790:Occupations; D005082:Physical Exertion / Q000502:physiology*; D011481:Protective Clothing; D020127:Recovery of Function / Q000502:physiology; D014937:Work