Intersegmental differences in facial warmth sensitivity during rest, passive heat and exercise

Figures & data

Figure 1. Six facial regions for the measurements of facial temperatures and warmth sensitivity. (A) forehead, (B) nose, (C) cheekbone, (D) upper lip, (E) cheek and (F) chin.

Table 1. Mean temperatures (in °C at 11 min and 30 min of individual trials) during trials at thermoneutral, passive warming and exercise in a warm environment conditions.

Variables	Thermoneutral	Passive warming	Exercise
Forehead	35.06 ± 0.38, 35.61 ± 0.34	36.41 ± 0.21, 36.30 ± 0.32	36.48 ± 0.44, 36.98 ± 0.45
Cheekbone	34.08 ± 0.91, 34.68 ± 0.63	36.09 ± 0.37, 36.02 ± 0.24	35.87 ± 0.59, 36.10 ± 0.48
Cheek	34.24 ± 0.62, 34.77 ± 0.64	36.30 ± 0.23, 36.16 ± 0.28	36.56 ± 0.30, 36.77 ± 0.35
Nose	33.93 ± 0.87, 34.52 ± 0.71	36.20 ± 0.22, 36.02 ± 0.30	36.49 ± 0.25, 36.64 ± 0.31
Upper lip	34.17 ± 0.35, 34.70 ± 0.37	36.11 ± 0.40, 35.93 ± 0.20	36.02 ± 0.41, 36.13 ± 0.34
Chin	34.31 ± 0.35, 34.70 ± 0.37	35.85 ± 0.44, 35.79 ± 0.16	35.92 ± 0.34, 35.94 ± 0.45
Facial (weighted)	34.32 ± 0.35, 34.83 ± 0.43	36.16 ± 0.24, 36.05 ± 0.20	36.23 ± 0.28, 36.43 ± 0.29
Rectal	36.91 ± 0.28, 36.97 ± 0.29	36.79 ± 0.28, 36.79 ± 0.29	36.95 ± 0.26, 37.22 ± 0.24
Mean body (weighted)	35.97 ± 0.28, 36.02 ± 0.26	36.37 ± 0.24, 36.39 ± 0.29	36.84 ± 0.24, 37.11 ± 0.22

Table 2. Heat flux difference pairwise comparisons among the facial regions while adjusting for facial anthropometrics.

Parameter	Forehead	Nose	Cheekbone	Upper lip	Cheek	Chin
Forehead				○
Nose					○•
Cheekbone					○
Upper lip					○•♦
Cheek
Chin					○

Pairwise comparisons that are significantly different at p<.05 are indicated for three conditions: thermoneutral (○), passive warming (•) and exercise (♦). Face length, forehead length, face width and bigonial width were held constant at 12.4, 7.0, 13.2 and 10.1 cm, respectively.

Figure 2. Heat flux threshold of six facial regions across thermoneutral, passive warming and exercise conditions. Values are mean and standard deviation (n = 12).

Table 3. Regression model for perceived thermal comfort with physiological measures of face and core body temperatures.

Parameter	B	Standard error	95% confidence interval		Wald chi square	p value	Exp (B)	Lower	Upper
			Lower	Upper
Tface^a	0.63	0.08	0.48	0.78	68.76	<.001	1.87	1.62	2.17
Tco^a	0.53	0.35	–0.06	1.13	3.07	.080	1.71	0.94	3.10
Tface^b	0.35	0.12	0.12	0.59	8.48	.004	1.42	1.12	1.80
Tco^b	0.17	0.11	–0.05	0.39	2.39	.123	1.19	0.96	1.47

^a Face vs. core body temperatures.

^b Perceived thermal comfort vs. facial thermal sensations.