Thermal Perception and Thermal Devices Used on Body Parts Other Than Hand or Face

Most fundamental research on thermal perception focuses on the fingers or the hand. Also most existing and proposed thermal devices are meant to be applied to hand or fingers. However, if the hands are needed for other tasks, application of thermal stimulation to other body regions should be considered. This paper surveys the literature on thermal perception and thermal devices relevant to such other body regions. It starts with a short description of the experimental methods used in the various studies, such as the methods of limits, the two-alternative forced choice method, and magnitude estimation. This is followed by thermal psychophysical studies on detection, adaptation, spatial summation, and resolution. Next some striking thermal illusions are presented, such as a thermal grill and a seemingly continuously warming or cooling stimulus. Finally, the few studies on thermal communication and applications are summarized. These latter studies mainly focus on communicating emotions or playing computer games. The overall conclusion of this survey is that thermal devices should not focus on conveying complex messages, but especially in the areas of gaming or communication there seem to be interesting possibilities for further developments.