Table 1.

Values of environmental conditions (WBGT and rH) in air-conditioned and tropical conditions, as well as sensation of fatigue, thermal comfort (from −3: very uncomfortable to + 3: very comfortable), thermal sensation (from −3: very cold to + 3: very hot) of students in theory classes when exercise was performed mid-morning (i.e. 9am-11am), or when exercise was performed early-morning (i.e. 7am-9am). Variables and statistics are presented as means (SD), or medians (quartiles) where appropriate. Brackets annotated with # indicate a significant difference between the given pairs (condition×time interaction); † indicates a significant difference between the given pairs (condition effect), and * indicates a significant difference between the given pairs (time effect) (all ps < 0.05).

	when exercise was performed mid-morning (i.e. 9am-11am)				when exercise was performed early-morning (i.e. 7am-9am)
Theory classes	7am-9am		11am-1pm		9am-11am		11am-1pm
Environmental conditions WBGT in (°C) rH (%)	Tropical climate 26.7 ± 0.5 (82.0 ± 0.0)	Air-conditioned 22.7 ± 0.4 (76.4 ± 2.8)	Tropical climate 30.0 ± 0.6 (86.3 ± 0.0)	Air-conditioned 21.8 ± 0.2 (61.3 ± 1.2)	Air-conditioned 21.4 ± 0.7 (60.8 ± 0.0)	Tropical climate 29.4 ± 0.4 (93.1 ± 0.0)	Air-conditioned 21.1 ± 0.2 (56.7 ± 0.0)	Tropical climate 30.1 ± 0.4 (95.3 ± 0.0)
Sensation of fatigue	4.0 (2.2–5.0) †	3.0 (2.0–3.0)	6.0 (5.0–6.0) #†*	5.0 (3.0–5.0) *	4.0 (3.0–5.0)	6.0 (5.0–6.0) #†	4.0 (3.0–5.0)	5.0 (5.0–5.0) #*
Thermal comfort	−1.0 (−2.0- −1.0) #†	2.0 (1.0–2.0)	−2.0 (−2.0- −1.0) #†	1.5 (1.0–2.0)	1.0 (0.0–2.0)	−2.0 (−2.0- −0.5) #†	1.0 (0.0–2.0)	−1.0 (−2.0- −1.0) #†
Thermal sensation	1.5 (1.0–2.0) #†	0.0 (−1.0–0.0)	2.0 (1.0–2.0) #†	0.0 (0.0–0.0)	0.0 (−0.5–0.0)	2.0 (1.0–2.0) #†	0.0 (−1.0–0.0)	1.0 (1.0–2.0) #†