Keeping warm and keeping cool have been everyday activities for people since time immemorial. But they proceed at an almost un conscious level of culture. for these actions are so common and usually so well integrated with all the other aspects of the culture that people don't often notice their particular character as a response to thermal need. It is only the rare literary traveler who may remark how a peoples' customs are suited to the local climatea subject for travel essays only slightly more sophisticated than remarking on the weather itself. And yet from the minute scale of gesture and posture to the grand scale of ritual and festivals, social customs often involve a thermal aspect. The image of a Southern lady nervously fanning herself is that of a coquette using the fan as a prop for flirting, rather than a woman merely trying to cool herself. Europeans have the custom of using furniture, chairs and beds, to raise themselves conveniently above the cold air that accumulates at floor level. Hindus, on the other hand, use no such furniture but sit directly on the floor where they benefit from the extra coolness held in the ground. Christmas is known as a religious festival. Yet the notion of celebrating Christmas in the southern hemisphere at the height of midsummer heat is slightly unsettling to people in the northern hemisphere. In spite of its religious basis, Christmas has strong connotations of being a warm, cozy time set in contrast to midwinter cold. Similarly every culture has its set of rituals customs, and special activities associated with each season.