Thermal environment

The thermal environment has a major influence on people's performance, sense of well-being and their health. The two chief factors that influence people's thermal comfort (too warm, pleasant, too cold, etc.) are:

• the ambient conditions, such as the thermal environment, interior layout, building structure, and
• their physical and psychological state or the physical loads and psychological stress to which they are subjected.

Within certain limits, the human body can adapt to changes in the thermal environment, depending on the person's metabolic rate. Outside of those limits, humans' heat balance fails and they are unable to regulate their temperature. This puts increased strain on the cardiovascular system. In turn, this can cause temporary disorders, e.g. circulatory problems or nausea, or - if exposure is prolonged - illness.

Even if the overall assessment of the thermal environment is positive, individual thermal or exposure factors can cause or aggravate temporary discomfort or, if exposure is prolonged, illness if they rise above or drop below certain ranges. An example of such factors is draught.