Table 1. Thermoregulatory and hemodynamic variables.
Rest (1st session) | HS (2nd session) | FHC (3rd session) | WBC (4th session) | |
---|---|---|---|---|
Esophageal temperature, °C | 36.71 ± 0.23 | 38.01 ± 0.20* | 37.95 ± 0.18* | 37.05 ± 0.21*†‡ |
External canal temperature, °C | 36.98 ± 0.28 | 38.10 ± 0.34* | 37.77 ± 0.32* | 37.01 ± 0.42†‡ |
Mean skin temperature, °C | 34.27 ± 0.63 | 38.93 ± 0.58* | 38.53 ± 0.84* | 34.34 ± 0.79†‡ |
Local skin temperature, °C | ||||
Forehead | 32.8 ± 1.1 | 34.5 ± 0.7* | 31.3 ± 0.9*† | 31.1 ± 1.5*† |
Forearm | 33.0 ± 0.9 | 36.9 ± 1.3* | 36.8 ± 1.5* | 33.2 ± 1.7†‡ |
CVC, au/mmHg | ||||
Forehead | 0.47 ± 0.17 | 1.53 ± 0.61* | 1.42 ± 0.47*† | 0.82 ± 0.52*†‡ |
Forearm | 0.14 ± 0.12 | 0.90 ± 0.36* | 0.88 ± 0.34* | 0.53 ± 0.26*†‡ |
Heart rate, bpm | 63.3 ± 7.3 | 105.4 ± 12.2* | 102.8 ± 11.4* | 73.4 ± 11.7*† |
Mean arterial blood pressure, mmHg | 91.7 ± 8.0 | 88.8 ± 7.7 | 87.4 ± 6.1 | 97.1 ± 8.8*† |
Blood flow, ml/min | ||||
Common carotid artery | 506.5 ± 89.4 | 746.6 ± 131.7* | 700.7 ± 156.4* | 475.4 ± 79.7†‡ |
Internal carotid artery | 356.9 ± 86.4 | 306.2 ± 74.5* | 376.1 ± 118.2† | 345.8 ± 107.2‡ |
External carotid artery (estimated) | 149.6 ± 63.6 | 440.5 ± 80.1* | 324.6 ± 107.5*† | 129.7 ± 59.8†‡ |
HS; whole body heat stress, FHC; local face and head cooling during heat stress, WBC; whole body cooling (i.e. recovery).
CVC; cutaneous vascular conductance. Data except for blood flow measured by ultrasound were averaged during the task in each session.
Values are the mean ± SD. * P < 0.05 from the 1st session; † from the 2nd session; ‡ from the 3rd session.