Table 2.
Baseline values.
| Younger | ‘At Risk’ | |
|---|---|---|
| Body Temperatures | ||
| Mean skin temperature (°C) | 31.9 ± 0.7 | 31.2 ± 1.0 |
| Internal temperature (°C) | 37.2 ± 0.3 | 37.0 ± 0.3 |
| Tbody1:1 (°C) | 34.5 ± 0.3 | 34.1 ± 0.6 Y |
| Tbody3:1 (°C) | 35.4 ± 0.2 | 35.1 ± 0.4 Y |
| Tbody9:1 (°C) | 36.7 ± 0.3 | 36.4 ± 0.3 Y |
| Hemodynamics | ||
| Mean arterial pressure (mmHg) | 83 ± 8 | 90 ± 6 Y |
| Systolic pressure (mmHg) | 113 ± 12 | 126 ± 10 Y |
| Diastolic pressure (mmHg) | 68 ± 7 | 73 ± 6 |
| Heart rate (bpm) | 75 ± 9 | 67 ± 10 |
| Stroke volume (mL/beat) | 81 ± 8 | 90 ± 12 Y |
| Cardiac output (L/min) | 6.0 ± 1.1 | 6.0 ± 0.7 |
| TPR (mmHg/L/min) | 16.4 ± 2.8 | 18.2 ± 2.2 |
| RPP (mmHg x bpm / 1000) | 8.4 ± 1.6 | 8.4 ± 1.4 |
| Cardiac power output (W) | 1.1 ± 0.3 | 1.2 ± 0.2 |
| Stroke work (mL / beat x mmHg) | 6.6 ± 1.1 | 8.2 ± 1.2 Y |
| Autonomic Thermoeffectors | ||
| Fingertip SkBF (PU) | 232 ± 167 | 173 ± 150 |
| Fingertip CVC (PU/mmHg) | 1.8 ± 1.1 | 1.6 ± 1.3 |
| Forearm SkBF (PU) | 28 ± 19 | 31 ± 8 |
| Forearm CVC (PU/mmHg) | 0.32 ± 0.24 | 0.29 ± 0.08 |
| Chest sweat rate (mg/min/cm2) | 0.05 ± 0.02 | 0.06 ± 0.02 |
| Forearm sweat rate (mg/min/cm2) | 0.06 ± 0.01 | 0.07 ± 0.01 |
| Metabolic heat production (W/m2) | 60 ± 10 | 56 ± 13 |
| Perceptions | ||
| Thermal discomfort (a.u.) | 1.1 ± 0.2 | 1.2 ± 0.4 |
| Thermal sensation (a.u.) | 3.9 ± 0.4 | 3.7 ± 0.4 |
| Sweating (a.u.) | 0.0 ± 0.0 | 0.0 ± 0.0 |
| Shivering (a.u.) | 0.2 ± 0.4 | 0.0 ± 0.0 |
Mean ± SD, Younger: n = 12, ‘At Risk’: n = 6, Tbody1:1: mean body temperature with internal and mean skin temperatures weighted 1:1, Tbody3:1: mean body temperature with internal and mean skin temperatures weighted 3:1, Tbody9:1: mean body temperature with internal and mean skin temperatures weighted 9:1, TPR: total peripheral resistance, RPP: rate pressure product, SkBF: skin blood flow, CVC: cutaneous vascular conductance,
Y
different from younger (P ≤ 0.03)