| Keywords |
Agricultural work; Fan-cooling vest; Heat stress; The elderly; Clothing microclimates |
| Abstract |
This study examined the effects of an air-ventilated vest on reducing heat strain in a hot and humid environment. Nine healthy young males (24.6 ± 3.6 y) and nine healthy older males (60.4 ± 3.6 y) completed two experimental conditions at 33°C and 65%RH: an air-ventilated vest fan-off (CON, Control) and fan-on (ACV, Air-Cooling Vest). A trial consisted of a rest (20-min), two exercise bouts (20-min) separated by a seated break (10-min), and recovery (20-min) (90-min in total). Rectal temperature and mean skin temperature were significantly lower for ACV than for CON in both age groups. Body heat storage was significantly lower for ACV than for CON in both age groups: 67.7 ± 8.8 (ACV) vs. 79.5 ± 7.5 W·m (CON) in young males and 36.6 -2 ± 12.7 vs. 55.4 ± 9.5 W·m-2 in older males (P < 0.05). Heart rate did not differ significantly between the two vest conditions for both young and older groups. Clothing microclimate temperature and humidity in the innermost and outer layers during several experimental periods were reduced for ACV, although humidity remained above the comfort range. Thermal sensation and humidity sensation for older males were improved for ACV. These findings suggest that wearing air-ventilated vests could reduce thermo-physiological and psychological heat strain during work for older adults as well as young adults in hot and humid environments. |