Influence of clothing and body-fat insulation on thermal adjustments to cold-water stress.

Male volunteers were divided into a low body fat (L) group (X = 10.6%, N = 5) and moderate fat (M) group (X = 18.6%, N = 5). Each was dressed in both dry suit plus medium insulation undergarment (DS-M) and dry suit plus heavy insulation (DS-H) and immersed in 10 and 15 degrees C water for 3 h. In 10 degrees C water, through not significantly different, rectal temperature (Tre) at h 3 was slightly higher in M (DS-M 36.4 degrees C, DS-H 36.5 degrees C) compared with L (DS-M 35.9 degrees C, DS-H 36.3 degrees C), whereas mean skin temperature (Tsk) and metabolic rate (MR) were in general, slightly lower for M(DS-M 23.6 degrees C, 184 W; DS-H 25.5 degrees C, 147 W, respectively). Over time the metabolic and thermal responses tended to stabilize after 120 min of immersion in both groups. Similar responses were observed in 15 degrees C water. These data suggested that despite the variation in body fatness, minimal thermal differences between groups were noted because of the attenuating effects of the insulated clothing.