The impact of suppressing a structural fire on firefighter hydration

Firefighting is perceived to be a highly stressful occupation with firefighters having to operate in extreme heat conditions whilst wearing personal protective equipment with limited vapor permeability. The impacts of both environment and clothing have the potential to induce heat illness. The aim of this research study was to investigate the effect of structural fire suppression on firefighter hydration status. Seven fully qualified male firefighters (mean age = 34.14 ± 7.69 yrs.) from an Australian fire and rescue service were exposed to a ‘live’ fire scenario. During this scenario the firefighters undertook active structural fire suppression and victim rescue tasks. The main outcome measures were of Urine Specific Gravity (USG), body weight, tympanic membrane temperature and skin temperature were measured pre and post task. Firefighter’s were already approaching a dehydrated state prior to starting the scenario (mean USG = 1.019 ± 0.008), there was a significant change in body mass (ρ < 0.001: 1.2%), body temperatures measures (ρ = 0.004: 3.1%) and tympanic membrane temperature (ρ = 0.004: 3.7%) following fire suppression. There was no significant change in USG pre and post task. Firefighters may commence duty in a dehydrated state. Furthermore structural fire suppression will increase their body temperature and reduced their hydration status as measured by body weight but not necessarily USG. Measures need to be taken to ensure that firefighters are hydrated and maintain a hydrated state prior to fire suppression tasks and, given the potential fluid loss during a task, that post-event hydration support and education is provided.