Effects of Local Cold and Heat Stimuli on Cutaneous Thermal Sensitivity and Inter-Threshold Zone at Rest and During Exercise

PURPOSE: The primary objective of this study was to investigate the effects of local cold and heat stimuli on cutaneous thermal sensitivity and inter-threshold zone at rest and during exercise. METHODS: Cutaneous warm and cold thresholds were measured on two body regions (forehead and hand) in three types of local thermal stress environments (neutral, heat, cold) using a method of limit in sixteen young, healthy male subjects (25.44±2.28 years) at rest and during exercise. RESULTS: The results showed that the thermal inter-threshold zone was wider on the hand than on the forehead under thermal stress conditions at rest and during exercise. The thermal inter-threshold zone on both body regions widened with exercise (p<.05). Exercise significantly blunted both the warm and cold sensitivity in the forehead (p<.05), but only cold sensitivity in the hand (p<.05). Moreover, the thermal inter-threshold zone on both the forehead and hand became significantly wider when heat or cold stress was applied to the local body region (p<.001). In the forehead, warm and cold sensitivity were significantly blunted in both heat and cold stress environments (p<.05), whereas in the hard they were significantly blunted only in the heat stress environment (p<.01). CONCLUSIONS: In conclusion, the present study showed that the forehead is more sensitive to both warm and cold stimuli than the hand, regardless of thermal stress or exercise. Furthermore, the thermal inter-threshold zone on both the forehead and the hand widened with exercise and local thermal stimuli.