Moisture-wicking clothing but not a spacer garment improves perceived thermal strain in Dutch military personnel

This study evaluated the effects of moisture-wicking clothing and spacer garments on heat strain among Royal Netherlands Marechaussee personnel. In a within-subject design, 19 participants (4 females, 15 males) stationed in the Dutch Caribbean participated in the study; were scheduled to complete 4 shifts while wearing their usual gear, a spacer garment, a moisture-wicking garment, or both a spacer garment and a moisture-wicking garment. Thermal sensation and comfort were assessed hourly, and skin temperatures were continuously monitored. Linear mixed models showed that moisture-wicking clothing without a spacer garment improved thermal comfort (-3 to +3) by 0.49 points (95% CI: 0.16 to 0.82) without affecting mean skin temperature, while standard gear with a spacer garment reduced thermal comfort by 0.36 points (95% CI: -0.68 to -0.04) and increased chest skin temperature by 0.41 °C (95% CI: 0.04 to 0.78). Moisture-wicking clothing enhances perceived comfort, whereas spacer garments may increase thermal strain.