Effects of Two Cooling Garments on Post-exercise Thermal Comfort of Female Subjects in the Heat

The purpose of the study was to investigate and compare the effect of two cooling garments with phase change material (PCM) and ventilation on thermal comfort. Eight female university students (age 24 +/- 1 years; height 161 +/- 4 cm; body weight 54 +/- 4 kg) exercised on a treadmill in an environment of 32 degrees C with 50 % relative humidity. Tests in three conditions were carried out after moderate exercise with t-shirt and shorts: cooling with a PCM vest (PCM); cooling with a ventilation jacket (VEN) and without cooling clothing (natural cooling, a control condition, CON). Results showed that no significant differences were observed in the mean skin temperature and heart rate among the two cooling garment conditions and the control condition (p>0.05). The local torso skin temperature was observed with significant difference among the three conditions (p<0.05) and it was mostly reduced by 0.7 degrees C and 0.9 degrees C, reSpectively in PCM and VEN. Significant differences were observed in the clothing torso micro-climate temperature and humidity among the three testing scenarios (p<0.05). The clothing micro-climate temperature was dropped by 2 degrees C in PCM and 0.8 degrees C in VEN. The clothing micro-climate humidity in PCM was 40 % higher than that in YEN after 30 minutes cooling. The perceived thermal sensation was the lowest in PCM whereas the perceived skin wettedness sensation was the lowest in VEN.