A man walks in thick clothing on a street in Changsha, capital of central China's Hunan Province, April 30, 2013. Temperature in Changsha dropped significantly on April 30 due to cold air. (Xinhua/Long hongtao)

A woman rides in thick clothing on a street in Changsha, capital of central China's Hunan Province, April 30, 2013. Temperature in Changsha dropped significantly on April 30 due to cold air. (Xinhua/Long hongtao)

A man rides in thick clothing on a street in Changsha, capital of central China's Hunan Province, April 30, 2013. Temperature in Changsha dropped significantly on April 30 due to cold air. (Xinhua/Long hongtao)