Human biometeorology is quite an old science: during the times of Hippokrates in ancient Greece the influence of weather changes on physiological processes in the human body were considered to exist. However, not until the progress in modern statistics, physics and physiology in the course of this century provided quantitative methods did human-biometeorology become an acknowledged natural science. In the first half of this century primarily the explanation of the phenomena of reactions of the body to weather changes was the general objective. In the second half of this century quantitative descriptions of thermal interchanges between the human body and the environment by means of energy balance models of the human body have gained increasing importance. The methods of modern human biometeorology increasingly are acknowledged by workers in disciplines of potential application, such as urban or regional planners or air conditioning engineers. Human biometeorology tries to assess all atmospheric influences in its entirety, including the air pollution pattern. The discipline considers itself as branch of science which is tied closely to environmental meteorology and environmental medicine.