Warmer temperatures are causing malaria to spread to higher altitudes, a study suggests.
Researchers have found that people living in the highlands of Africa and South America are at an increased risk of catching the mosquito-borne disease during hotter years.
They believe that temperature rises in the future could result in millions of additional cases in some areas.
The research is published in the journal Science.
Prof Mercedes Pascual, from the University of Michigan in the US, who carried out the research, said: “The impact in terms of increasing the risk of exposure to disease is very large.”