Thermal Insulation and Body Temperature Wearing a Thermal Swimsuit during Water Immersion

Abstract

This study evaluated the effects of a thermal swimsuit on body temperatures, thermoregulatory responses and thermal insulation during 60 min water immersion at rest. Ten healthy male subjects wearing either thermal swimsuits or normal swimsuits were immersed in water (26°C or 29°C). Esophageal temperature, skin temperatures and oxygen consumption were measured during the experiments. Metabolic heat production was calculated from oxygen consumption. Heat loss from skin to the water was calculated from the metabolic heat production and the change in mean body temperature during water immersion. Total insulation and tissue insulation were estimated by dividing the temperature difference between the esophagus and the water or the esophagus and the skin with heat loss from the skin. Esophageal temperature with a thermal swimsuit was higher than that with a normal swimsuit at the end of immersion in both water temperature conditions (pϽ0.05). Oxygen consumption, metabolic heat production and heat loss from the skin were less with the thermal swimsuit than with a normal swimsuit in both water temperatures (pϽ0.05). Total insulation with the thermal swimsuit was higher than that with a normal swimsuit due to insulation of the suit at both water temperatures (pϽ0.05). Tissue insulation was similar in all four conditions, but significantly higher with the thermal swimsuit in both water temperature conditions (pϽ0.05), perhaps due to of the attenuation of shivering during immersion with a thermal swimsuit. A thermal swimsuit can increase total insulation and reduce heat loss from the skin. Therefore, subjects with thermal swimsuits can maintain higher body temperatures than with a normal swimsuit and reduce shivering thermo-genesis.

Human Physiology in an Aquatic Environment

“…Wearing thermal protection gear provides insulation but results in nonuniform and higher skin temperatures. Although there are apparently no differences in thermal sensation and shivering thermogenesis when T s decreases uniformly versus nonuniformly (wet suit covering trunk upper arms and legs), tissue insulation (vasoconstriction) was significantly higher when T s changes were nonuniform due to augmented cold sensory input form the periphery (404). It has also been noted that when T s were maintained at a higher level during cold immersion the temperature gradient between body and water actually increases and this may result in greater heat loss and decrease in core temperature (16,267,305).…”

“…This may be an issue with wet suits. Wearing a wet suit in cold water resulted in a higher esophageal temperature and attenuation of shivering and thus V O 2 did not increase as much due to the higher insulation (404).…”

Effect of non-uniform skin temperature on thermoregulatory response during water immersion

“…In NUST condition, subjects wore a partial coverage wetsuit (PCWS, 206776-09; Footmark Co. Ltd., Japan) at 26°C water, which made skin temperature distribution higher at trunk and lower at limbs compared to UST condition. On the basis of the author's previous work using PCWS (Wakabayashi et al 2006a), the water temperature of the two conditions was set at 29°C for UST and 26°C for NUST, which resulted in a similar mean skin temperature for both the conditions. Additionally, the water temperature in UST condition was similar to the water temperature (28.4°C) in the previous research (Choi et al 2003), which brings about cold-induced shivering thermogenesis and vasoconstriction.…”

“…In our previous studies, the effect of a partial coverage wetsuit (PCWS; covering trunk region, upper arms, and thighs) during cool water immersion was examined (Wakabayashi et al 2005(Wakabayashi et al , 2006a(Wakabayashi et al , b, 2007, and their specific characteristics differing from full wetsuits were observed. The tissue insulation (I tissue ) with a PCWS was similar to the naked condition, while previous study reported that wearing wetsuits decreased I tissue (Kang et al 1983;Shiraki et al 1986).…”

“…The tissue insulation (I tissue ) with a PCWS was similar to the naked condition, while previous study reported that wearing wetsuits decreased I tissue (Kang et al 1983;Shiraki et al 1986). PCWS directly exposed distal extremities, including hands, feet, forearms and calves, to water more than wetsuits, which might be a sufficient sensory input to induce vasoconstriction similar to the naked condition (Wakabayashi et al 2006a). Since the non-uniform skin temperature (NUST) condition wearing PCWS, higher in trunk region and lower in the limbs, may have complex effects on thermoregulatory response, it is necessary to compare the thermoregulatory response in NUST condition to that in uniform skin temperature (UST) condition on a similar mean skin temperature.…”