Increasing hand efficiency at cold temperatures by training hand vasodilation with a classical conditioning-biofeedback overlap design.

The prolonged exposure of hands to cold environments leads to substantial cold pain and severe deterioration of manual dexterity, finger dexterity, hand strength, and tactile sensitivity. This study taught volunteers to warm their hands at -14 degrees Celsius and measured the hand efficiency effects. The subjects were six male and female nonsmoking volunteers. All research was conducted in a cold chamber during the warm summer months to eliminate seasonal factors. A combined multiple-baseline/ABA single-subject design with multiple replications was used. Each subject's hand performance was obtained for both hands in warm and in cold conditions. One hand was trained and both hands were retested in the cold. The second hand was trained and both hands were retested in the cold. Finally, the subject inhibited warming while in the cold (treatment removal) and both hands were tested again. The treatment itself used biofeedback instrumentation to extend and enlarge previously classically conditioned vasodilative episodes. The procedure was found to be effective for bringing about temperature changes in the cold. Large treatment effects were found on all hand efficiency measures. The results suggest wide implications for the workplace, for theory, and for future research.