The effects of moderate cold stress on bare or lightly covered hands was determined on five subjects exposed to alternate cycles of hand cooling at rest in a 0° C controlled environmental chamber and rewarming at rest in a room at 24° C. Repeated cycles of hand cooling and rewarming were characterized by a decrease in time for the hands to become cold and an increase in time for the hands to become warm, resulting in a progressively decreasing percentage of the elapsed time spent in the cold environment. Although the subjects were adequately clothed except for hand covering, body and skin temperatures fluctuated in relation to the exposure to the cold or warm environment. A relatively steady decrease in rectal temperature throughout the duration of the experimental period indicates that much of the heat loss from the hands was replaced by heat from the body "core" even though the hands were rewarmed in a warm environment. It appears that clothing adequate to protect the body will not prevent deep body heat loss from exposed hands, and other approaches to the problem of performing delicate manual tasks in a cold environment must be considered.