An Indian girl cools off at a tube well in Calcutta, capital of eastern Indian state West Bengal, on May 17, 2012. The temperature of the northern India reaches more than 40 degrees Celsius, and the heat wave conditions prevail in Calcutta city and five south Bengal districts. [Xinhua]

An Indian boy cools off at a tube well in Calcutta, capital of eastern Indian state West Bengal, on May 17, 2012. The temperature of the northern India reaches more than 40 degrees Celsius, and the heat wave conditions prevail in Calcutta city and five south Bengal districts. [Xinhua]

An Indian woman eats icecream in Calcutta, capital of eastern Indian state West Bengal, on May 17, 2012. The temperature of the northern India reaches more than 40 degrees Celsius, and the heat wave conditions prevail in Calcutta city and five south Bengal districts. [Xinhua]

An Indian shop owner cools off with a hand-made fan in Calcutta, capital of eastern Indian state West Bengal, on May 17, 2012. The temperature of the northern India reaches more than 40 degrees Celsius, and the heat wave conditions prevail in Calcutta city and five south Bengal districts. [Xinhua]