Response to thermal and physical strain during flashover training in Croatian firefighters

•Flashover training (FOT) induced a mild physiological cardiovascular response.•More than 25% FOT attendees were obese.•Elevated basal blood pressure was found in >50% FOT attendees.•Croatian firefighters need to improve their physical fitness.

Flashover training (FOT) for firefighters is a simulation of the flashover phenomenon under controlled conditions. This study assessed arterial blood pressure (BP) and its response to thermal and physical strain during FOT in 48 professional and 18 volunteer firefighters.A high prevalence of obesity (27%), basal hypertensive (53%) and prehypertensive (33%) BP values was found. FOT induced mild hyperthermia and physical strain (average increase of 1.1 °C in tympanic temperature and 61% of the maximal heart beat predicted for age). Compared to professional firefighters, FOT in the volunteers induced a higher increase in pulse (P = 0.050) and tympanic temperature (P = 0.025). Systolic BP did not vary significantly, and diastolic BP slightly decreased in both groups.Results confirm that FOT induced only physiological cardiovascular responses to thermal and physical strain in firefighters. High prevalence of obesity and elevated BP values indicate the need for better physical fitness and BP control among firefighters.