The physiological basis for thermal comfort in different climates; a preliminary study

Thermal comfort is very important for optimal functioning of humans. It gives information about the thermal state of the body, by which the human body can take physiological measures or the human can take behavioural measures to maintain thermal control. This will be the base of this study. Thermal comfort is sensed by warm and cold receptors in the skin, but also in deeper structures of the body. Pain receptors play a role in the detection of extreme cold and heat. The hypothalamus is the regulation and detection centre of temperature in the body, receiving afferent information of the receptors and sending efferent information to the effectors by which the body controls its temperature. Thermal comfort is determined by the temperature, pain and comfort sensations of the body. Also the experience of humidity can influence the comfort feelings. A problem in the study of comfort is the large diversity of the subjective scales used, which makes it difficult to compare the developed models. The goal of this study however is to make an inventory of most commonly used models and to judge them on useability for the existing thermoregulatory models. Local sensations are described as power functions based on psycho-physical functions and global sensations are described as linear functions. The most important dependent variables in global thermal comfort are core temperature, temperature of the extremities and temperature of the environment. In local thermal comfort and pain, temperature of the skin is most important. Humidity sensation of the skin is determined by temperature of the core, sweat production and local relative humidity of the skin.