Table 2.

Distribution of progressive heat stress trials by the four types of trials and clothing for metabolic rate, core temperature, heart rate, and physiological strain index at the upper limit of the prescriptive zone; and the distributions by sex for the four types of trials

			Number of Trials†	MR, W	Tc, °C	HR, beats/min
	Study*	Clothing**		Means ± SD	Means ± SD	Means ± SD
PSU	Bike	SC	91	161 ± 37	37.38 ± 0.27	94 ± 14
	Walk	SC	99	280 ± 57	37.66 ± 0.35	113 ± 21
USF	Met Trials	WC	90	347 ± 118	37.67 ± 0.30	117 ± 20
	RH Trials	WC	86	305 ± 82	37.77 ± 0.36	117 ± 16
		Sex
PSU	Bike	Men	49	183 ± 31	37.26 ± 0.22	91 ± 11
		Women	42	135 ± 24	37.51 ± 0.25	97 ± 16
	Walk	Men	52	314 ± 47	37.54 ± 0.34	105 ± 16
		Women	47	243 ± 42	37.79 ± 0.31	121 ± 21
USF	Met Trials	Men	66	369 ± 115	37.68 ± 0.32	114 ± 17
		Women	24	287 ± 107	37.65 ± 0.25	126 ± 24
	RH Trials	Men	55	343 ± 65	37.70 ± 0.33	112 ± 16
		Women	31	236 ± 63	37.90 ± 0.38	127 ± 13

Values are means ± SD. HR, heart rate; MR, metabolic rate; T_c, core temperature; ULPZ, upper limit of the prescriptive zone.

^*Study: Bike (light metabolic rate); Walk (moderate metabolic rate); Met Trials (low, moderate, and high metabolic rates at 50% relative humidity); RH trials (20, 50, 70% relative humidity at moderate metabolic rate); **clothing: SC (semiclothed); WC (cotton shirt/trousers or cotton coverall; †note that there was considerable overlap in participants between the two Pennsylvania State University (PSU) studies with each participant completing about two trials in each study. The University of South Florida (USF) studies used fewer participants, each participant completed about 6 trials (2 types of woven clothing at either three metabolic rates or three relative humidity levels) and no overlap between studies.