More than a billion people are at risk from a lack of air conditioning and refrigeration to keep them cool and to preserve food and medicines as global warming brings more high temperatures, a study Monday showed.

More electricity demand for fridges, fans and other appliances will add to man-made climate change unless power generators shift from fossil fuels to cleaner energies, according to the report by the non-profit Sustainable Energy for All group.

About 1.1 billion people in Asia, Africa and Latin America — 470 million in rural areas and 630 million slum dwellers in cities — are at risk among the world's 7.6 billion people, it said.