The Aedes aegypti mosquito, which spreads dengue fever and yellow fever, has traditionally been unable to survive at altitudes higher than 1,000 meters because of colder temperatures there. But with recent warming trends, those mosquitoes have now been reported at 1,240 meters in Costa Rica and at 2,200 meters in Columbia. Malaria-bearing mosquitoes, too, have moved to higher elevations in central Africa, Asia, and parts of Latin America, triggering new outbreaks of the disease.