Table 2.

HWA outdoors and indoors stratified by workload and time of day using WBGT data.

Time interval		6–9 a.m.		9 a.m.–12 p.m.		12–3 p.m.a		3–5 p.m.
HWA (minutes)		Mean ± SD [95% CI]
Setting	Workload
Outdoors	Moderate	37 ± 26	[33, 40]	15 ± 21	[13, 18]	27 ± 21	[24, 29]	30 ± 20	[27, 33]
	Heavy	29 ± 25	[26, 32]	9 ± 15	[7, 11]	15 ± 16	[13, 17]	18 ± 17	[15, 20]
Indoors	Moderate	50 ± 19	[47, 52]	44 ± 22	[41, 46]	43 ± 21	[40, 45]	45 ± 21	[41, 48]
	Heavy	42 ± 21	[39, 45]	32 ± 22	[30, 35]	30 ± 20	[27, 32]	33 ± 21	[30, 37]

^aMandatory afternoon outdoor work ban (12–3 p.m.).