AbstractThis thesis aimed to provide evidence informed recommendations for UK Fire Service Instructor (FSI) working practices to reduce the risk of symptoms of ill health and cardiovascular events. Study 1 provides a detailed insight into the working practices of FSI, collected via a survey. Data indicated that FSI had little guidance on hydration, cooling methods, or fire exposure (wear) limits. In addition, 41% of FSI reported symptoms of ill health including: broken sleep, fatigue, headaches, mood swings, and coughing/breathing problems. To understand the acute responses to working practices, FSI were monitored during a wearing day for Study 2. A multi-compartment exposure, and the condition setter role within it, were noted to cause the greatest rise in core temperature. Training days that included a multi-compartment exposure also resulted in an increased inflammatory response. Pre-cooling methods, to minimise the rise in core temperature and inflammation, were assessed in a laboratory simulated wear in Study 3. A single 500 ml bolus of ice slurry was the only practical pre-cooling method to significantly reduce core temperature. To assess the chronic impact that repeated wears had on FSI, a heat occupational tolerance test (HOTT) was designed and assessed as valid and reliable in Study 4. Using the HOTT the tolerance status of FSI was compared to non-wearing controls in Study 5. FSI displayed an increased heat tolerance, suggestive of an acclimatised state. Improved tolerance was associated with an increased prevalence of ill health. Combined with elevated cytokine levels, this indicated FSI may exhibit a maladaptive response to frequent wears. Study 6 subsequently involved the collection of resting blood samples from 110 fire service personnel and demonstrated that FSI expressed signs of chronic systemic inflammation, which was linked to the number of wears that had been completed and symptoms of ill health similar to overtraining. FSI also exhibited elevated markers associated with cardiovascular risk. The informally suggested limit of 9 wears a month was found to be appropriate guidance, with those above the limit being 6 - 12 times more likely to express “at risk” levels for predictors of cardiovascular events and 16 times more likely to experience symptoms of ill health.
This thesis establishes that FSI are a unique population with a common collection of symptoms of ill health, and are at a chronic risk of elevated predictors of cardiovascular events and an overtraining like syndrome. To reduce the acute levels of inflammation and core temperature rises to fire exposures it is recommended that FSI roles are rotated, that exposure type is considered in course planning and that ice slurry pre-cooling is utilised. To reduce the prevalence of chronic systemic inflammation, symptoms of ill health, and cardiovascular risk, whilst maintaining an acclimatised state, a 9 wear per month limit is recommended.
|Date of Award||Sept 2018|
|Supervisor||Alan Richardson (Supervisor), Mark Hayes (Supervisor) & Peter Watt (Supervisor)|