There's a whole series of lectures for this graham.
Thermal comfort is affected by a number of factors; mean surface temp, wet bulb temp, dry bulb temp, RH, air velocity, clothing, metabolic rate etc etc.
These change according to the season and the temperature of a building has to adjust accordingly. Having said that very few buildings have adequate zoning of heating.
There was a prof called Fanger whos work provides the basis of most modern beliefs of comfort. Interesting stuff if you like that kind of thing