Old Firefighters Get More Heat Resilient Over Time, Study

Due to repeated occupational heat stress exposure, old firefighters are more capable of withstanding heat, claims a new study published in the journal of Occupational and Environmental Hygiene (JOEH).

The study says that firefighters who are chronically exposed to heat are more likely to show better heat adaptation than new firefighters who are less exposed to heat. Due to repeated heat stress exposure, veteran firefighters are more capable of withstanding challenging and strenuous work environment before they feel affected by the heat. The new entrants are more susceptible to heat stress and tend to end their tasks in a hurry.

"We found that the firefighters experienced reduced subjective feelings of thermal and cardiovascular strain during exercise compared to the non-firefighters, potentially indicative of greater heat resilience in firefighters due to the nature of their occupation," said study investigator Glen P. Kenny, PhD, a professor at the School of Human Kinetics at the University of Ottawa in Ontario, Canada. 

To prove this, the researchers analyzed a group of 51 years old, physically active non-firefighters and firefighters. In order to check the thermal, cardiovascular and hydration effects of repeated exposure to occupational heat stress, the two groups were placed in two heat stress conditions.

The researchers found no difference in the thermal and cardiovascular strain in the two groups of people. But compared to the older firefighters, the non firefighters felt more heat stressed and felt the task assigned was extremely challenging and tiring.

Kenny said, "If you have older workers who work in the heat, they are in a better position to handle working in the heat as compared to their non-heat-exposed counterparts. If they can better handle the heat stress, they can better perform challenging tasks without putting themselves at greater risks of injuries caused by impairments in mental function, alertness, concentration, motor dexterity and coordination."

"Our discovery is especially important given recent findings that aging can decrease an individual's ability to dissipate heat and therefore work in hot environments," added Kenny.

This finding contradicts the previous studies that link a person's aging to reduced ability to dissipate heat and work in a hot environment.