A view of the sunset in Haimen district, Nantong on July 11, the first day of sanfu, the hottest and dampest period of the year. [Photo/ntfabu.com]

Sanfu, also called China's "dog days of summer", refers to three 10-day periods that are predicted to have the hottest days of the year. This year's sanfu started on July 11 and will end on Aug 19.

As a millennium-old tradition, Chinese people are spending sanfu like their ancestors. In traditional Chinese medicine, sanfu is considered a particularly suitable time for treating illnesses. Sanfutie, a special treatment, has been used by Chinese people for hundreds of years.