In addition to the intense effort of firefighters during rescue operations and an adverse thermal environment, the properties of clothing can also hinder the performance of occupational activities. The heat load of firefighters during diversified effort in a climate chamber was compared for two types of protective clothing (barrack [B] clothing and barrack under special-purpose [S] clothing) at two levels of air temperature (20 and 30 °C). During testing, physiological parameters of heat strain were measured and subjective ratings were collected. There was a small increase in physiological parameters and subjective ratings at 20 °C in S clothing compared to the results in B clothing, whereas those differences were substantial at 30 °C. So, the structure of S clothing, which ensures protection of firefighters against high temperatures and flames, and its watertight layer make it significantly more difficult for the body to give off heat.
Keywords: firefighters; physical effort; protective clothing; thermal comfort; thermal strain.