For the ambulatory person with lower-limb amputation, insufficient management of perspiration can result in inadequate prosthesis adherence, reduced mobility, and discomfort. This study compared a dynamic air exchange (DAE) prosthesis designed to expel accumulated perspiration with a total surface bearing suction socket (Suction) that cannot. Five people with unilateral transtibial amputation participated in a randomized, crossover experiment. All subjects were given a 1 wk acclimation to each study prosthesis while we measured their step activity levels. A rest-walk-rest protocol, including a 30 min treadmill walk at a self-selected speed while wearing thermally insulative garments, was then used to observe residual-limb skin temperatures and perspiration. Afterward, subject opinions about the prostheses were assessed with questionnaires. During the week-long acclimation period, no statistical difference in step activity levels were detected between prostheses (p = 0.22), but this may have been due to self-reported behavioral modifications. During the rest-walk-rest protocol, no differences in skin temperatures were observed (p = 0.37). The DAE prosthesis accumulated 1.09 +/- 0.90 g and expelled 0.67 +/- 0.38 g of perspiration, while the Suction prosthesis accumulated 0.97 +/- 0.75 g. The questionnaire results suggest that participants were receptive to both prostheses. The DAE prosthesis was able to expel more than a third of the total perspiration, suggesting it may enable longer uninterrupted periods of perspiration-inducing activity.