The impact of different cooling modalities on the physiological responses in firefighters during strenuous work performed in high environmental temperatures

Eur J Appl Physiol. 2011 Jun;111(6):959-67. doi: 10.1007/s00421-010-1714-1. Epub 2010 Nov 16.

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.

Publication types

  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Body Temperature Regulation / physiology*
  • Cold Temperature
  • Environment
  • Fires
  • Hot Temperature* / adverse effects
  • Humans
  • Hypothermia, Induced / methods*
  • Immersion / physiopathology
  • Middle Aged
  • Occupational Exposure
  • Occupations
  • Physical Exertion / physiology*
  • Protective Clothing
  • Recovery of Function / physiology
  • Work