D. Gavhed et al., Face temperature and cardiorespiratory responses to wind in thermoneutral and cool subjects exposed to-10 degrees C, EUR J A PHY, 83(4-5), 2000, pp. 449-456
The effects of the thermal state of the body (slightly cool and neutral) an
d moderate wind speeds on face temperature, blood pressure, respiratory fun
ction and pain sensation during cold exposure were studied on eight healthy
male subjects. They were dressed in cold-protective clothing and precondit
ioned at + 20 degreesC (TN) and -5 degreesC (CO) for 60 min, then exposed t
o -10 degreesC and 0 m . s(-1) (NoW), 1 (W1) and 5 (W5) m . s(-1) wind for
30 min. Thus, each individual was exposed six times. The exposure to wind e
ntailed a combination of strong cooling of the bare face and mild body cool
ing. The forehead, cheek and nose temperatures decreased during cold exposu
re, and the decrease was greater at higher air velocities (P < 0.0001). All
subjects reported pain sensations at 5 m . s(-1). At the end of exposure o
nly the nose temperature was significantly lower in CO than in TN subjects,
it was about 2 <degrees>C and reached 0 degreesC in two experiments. The s
ystolic and diastolic blood pressure (SBP and DBP, respectively) increased
significantly by 7.7 and 5.9 mmHg, respectively, during preconditioning at
-5 degreesC, but did not change at + 20 degreesC. SEP and DBP increased dur
ing exposure to -10 degreesC in TN by approximately 9 mmHg. However, the to
tal average increase of blood pressure (1-90 min) was similar in TN and CO
(SBP 15 mmHg and DBP 13 mmHg). SEP and DBP increased more during exposure t
o 5 m . s(-1) at -10 degreesC than NoW. Blood pressure responses as observe
d in this study (SBP and DBP up to 51 and 45 mmHg, respectively) are potent
ial health risks for hypertensive individuals and angina patients. Respirat
ory functions (FVC, FEV1) were reduced by about 3% by the cold (-5 and -10
degreesC) compared to pre-experiment values. Furthermore, the Wind Chill In
dex seems to underestimate the cooling power of 5 m . s(-1) at -10 degreesC
of bare skin (e.g. face). Therefore it needs to be revised and we suggest
that it is expanded to include risk levels for pain sensation.