In this 2003 file photo, the Ibardin lake in southern French was almost dry due to a heat wave that killed 71,000 people, making it the most deadly heat wave in the world to date.
A heat wave in Russia in 2010 left more than 55,000 people dead.
In 2006, Europe had about 3,418 deaths directly attribed to the heat wave.
In 1998, about 2,541 deaths in India were attributed to the heat wave.
An Indian auto rickshaw driver rests on a hot summer day in Hyderabad, India, May 25, 2015. So far, more than 1,826 deaths have been attributed to the heat wave.