In the early days the Tibetans only own one chuba, usually of animal skin and lined with animal fleece. They wear it till it falls apart. It keeps them warm in those frigid winter temperatures and in summer they let one sleeve off their shoulder. If it gets really really hot they could have both sleeves off, the men become bare chested and the women bare breasted. There are old photographs in books that show this trend. However in modern times, they can easily get a summer chuba, made of lighter fabric and trimmed with all kinds of decorative trims. The shops in Xiahe has no shortage of fabrics, trims and other paraphernalia for dressing the authentic Tibetan way. I noticed these shops are usually owned by the Hui (Muslim) minority.