Our current knowledge of human thermal comfort is developed
by engineers and physiologists. The first concept began by a British
physician in 1774. Afterwards, engineers and physiologists developed
different indices relating temperature to comfort, and now,
building physicists use different thermal comfort standards.
Apparently, their endeavours were through two basic methods;
steady-state studies and field studies. Most of the steady-state
studies were prior to the field studies.
In the past, there have been two general approaches for determining
the thermal comfort: (a) climate chamber studies, and (b) field
studies: