The effect of short and continuous absorbent patch application on local skin temperature underneath

Objective. By attaching absorbent patches to the skin to collect sweat, an increase in local skin temperature (T_sk) underneath the patches seems unavoidable. Yet this effect has not been quantified. The present study investigates the effect of absorbent patch application on localT_skunderneath.Approach. Ten healthy participants cycled for 60 min at an exercise intensity relative to their body surface area (40 W.m^-2) in three environmental conditions (temperate: 25 °C 45% RH, hot-humid: 33 °C 65% RH and hot-dry: 40 °C 30% RH). The effect of short sweat sampling (i.e. from min 25-30 to min 55-60) onT_skwas examined on the right scapula.T_skof the left scapula served as control. The effect of continuous sweat sampling (i.e. four consecutive 15 min periods) onT_skwas examined on the right upper arm.T_skof the left upper arm served as control.Main results. Neither short nor continuous application of absorbent sweat patches affectedT_skunderneath the patches in the hot-humid and hot-dry condition (P > 0.05). In the temperate condition, continuous application led to a significant increase inT_skunderneath the patches during the first and second minute. This increase remained throughout the experiment (1.8 ± 0.6 °C;P < 0.001). Short application of sweat patches did not affect the localT_skunderneath (P > 0.05) in the temperate condition.Significance. To avoid a significant increase in localT_skunderneath sweat patches, continuous application should be prevented in, especially, a temperate condition. Timely removal of sweat patches should be taken into account during longer periods of collecting sweat in field or laboratories settings.