As a firefighter, you face a broad range of challenging environments, and working in turnout gear is tough on your body. You definitely need protection against extreme heat, but the vast majority of your calls don’t involve this kind of challenge. Nevertheless, heat is still a problem, and the heat you encounter during most calls can contribute to heat stress.
SMALL INCREASES MATTER
The human body can be extremely sensitive to small increases in core temperature. U.S. military studies have shown that once your temperature reaches 100°F, each increase of 0.1°F is physiologically significant, leading to an increased risk of heat exhaustion.
YOUR CHOICE OF PROTECTIVE BARRIER MATTERS
A recent human study evaluated the physiological impact of protective barriers currently available in turnout gear. Conducted by a third party, this study confirmed that wearing the GORE® PARALLON™ liner system delivered the highest breathability followed closely by GORE® CROSSTECH® black moisture barrier. Both of the GORE® protective barriers performed significantly better than the competition. In fact, 40 percent of the trial participants could not finish the test when wearing the competitive barrier because their heart rates exceeded their maximum rates, which were established as part of the safety criteria before the trial began.
THL VERSUS RET TEST METHODS
Testing the performance of the materials in your gear can provide valuable information for gear selection. The THL test has done a great deal of good for the firefighter, helping to improve how well gear can shed excess body heat; but it evaluates performance in a relatively mild environment, similar to a conditioned office space. And, it has been found that THL does not provide very useful information about how gear performs, particularly in warm or sunny conditions. The RET test can provide some of this valuable insight, which could be important to you in your gear selection.
In addition, THL did not predict the differences seen in the human trials, whereas the RET testing did.