Thermal information is not differentiated in our memory; rather it is retained as a quality, or underlying tone, associated with the whole experience of the place. It contributes to our sense of the particular personality, or spirit, that we identify with that place. In remembering the spirit of a place, we can anticipate that if we return, we will have the same sense of comfort or relaxation as before.
There is an underlying assumption that the best thermal environment never needs to be noticed, and that once an objectively "comfortable" thermal environment has been provided, all of our thermal needs will have been met. The use of all of our extremely sophisticated environmental control systems is directed to this one end—to produce standard comfort zone conditions.
Textbooks on water-system engineering state that supply mains are generally installed on the north side of the street in the Northern Hemisphere and on the south side in the Southern Hemisphere, so that the sun will warm them. In both hemispheres they are supposed to be on the east side of north-south streets, on the premise that the afternoon sun is warmer than the morning sun.
The predicted mean vote (PMV) was developed by Povl Ole Fanger at Kansas State University and the Technical University of Denmark as an empirical fit to the human sensation of thermal comfort. It was later adopted as an ISO standard. It predicts the average vote of a large group of people on the a seven-point thermal sensation scale where:
That is why for many years Irwin declined to allow his work to be photographed, because the image of the canvas was precisely what the painting was not about.
Indeed, the problem is even more complicated than that. For in a very real sense the achievement of these paintings was in their making, and the finished canvas at one level is only an incidental relic, a fossil of that original process of discovery: not only do you have to be present before these paintings in order to experience them, it may be that you have to have made them as well.