Environment impact is simulated by change in environmental temperature, humidity, air velocity, radiant temperature and/or solar radiation. Computer Simulator allows simulating step and gradual change of environmental characteristics. It can be simulated as total impact on human body as local effects on different parts of body. Computer Simulator can be adapted to change of environment from air to water, from outdoors to indoors et.al. Computer Simulator allows modeling of human stay in building taking into account room size and windows.