File(s) under permanent embargo
Reason: This item is currently closed access.
Isolating the independent effect of decreasing mean skin temperature on local thermal sensitivity of human hands and feet during cold stress
conference contributionposted on 07.12.2016, 09:24 by Davide Filingeri, Nathan B. Morris, Oliver E. Jay
Whether reductions in whole-body mean skin temperature (Tsk), with no concurrent changes in core temperature (Tc), alter local thermal sensitivity (TS) of human skin is currently unknown. On 4 separate occasions, 8 males (27±5y) underwent a 30-min whole-body cooling protocol (water-perfused suit: ~5°C), during which a quantitative thermo-sensory test, consisting of reporting (visual analogue scale) perceived magnitude of local warm (38°C) and cold (22°C) thermal stimuli (25-cm2 thermal probe) applied to hand (palm/dorsum) and foot (sole/dorsum), was performed before cooling and every 10min thereafter. The cooling protocol resulted in large progressive reductions in Tsk (10min: −3.36±0.67°C; 20min: −5.21±1.00°C; 30min: −6.32±1.14°C; p<0.001), with minimal changes in Tc (10min: −0.08±0.04°C; 20min: −0.07±0.07°C; 30min: −0.07±0.09°C; p<0.001). While no differences in TS to the local cold stimulus were observed for any skin region at any stage of the cooling protocol (ΔTS from baseline; 10min: −2.05±5.9%; 20min: −0.3±7.8%; 30min: −1.1±8.5%; p=0.790), a significant and progressive increase in warm TS occurred at each level of Tsk for all skin regions (10min: +4.9±7.5; 20 min: +6.1±4.5; 30 min: +7.9±6.1%; p=0.004). A significant association between decreasing levels of Tsk and increases in warm TS was observed (y= −1.217x+0.2139; R2=0.98; p=0.003), indicating a 1.4% increase in warm TS per 1°C drop in whole-body Tsk. Overall, the same local warm stimulus (hence same increase in skin temperature) was perceived to be warmer with progressive reductions in whole-body Tsk, indicating that, independently of Tc, decreases in whole-body Tsk significantly alter local warmth, but not cold, TS of human hands and feet.
Mr Morris was supported by a University of Sydney International Postgraduate Research Scholarship (IPRS). Dr Filingeri was supported by a Government of Australia Endeavour Fellowship