A major branch of bioclimatology that deals with effects of climate upon man. Currently, its major emphasis is on 1) the heat balance of the human body under different conditions of air temperature, humidity, and wind; 2) the effects of radiation, especially nuclear and ultraviolet, on genetics and general health; 3) the effects of atmospheric conditions and of types of changes of weather and climate on human health, vigor, and disease; and recently, 4) the effects of electrical conditions, including the atmospheric potential gradient and longwave radiations.