Malaria and dengue fever serve as prime examples of climate sensitive diseases. Malaria has been observed in non-endemic high elevations in Africa during unseasonably warm conditions. Freezing temperatures kill overwintering eggs of Aedes aegypti, the mosquito carrier of dengue and yellow fever. Warming trends, therefore, can shift vector and disease distribution to higher latitudes or altitudes, as was observed in Mexico when dengue reached an altitude of 1,700 meters during an unseasonably warm summer in 1988. In an earlier study in Mexico, the most important predictor of dengue prevalence in communities was found to be the median temperature during the rainy season.
Temperature also drives epidemic dynamics of dengue transmission.
Warmer water temperatures in breeding vessels reduces the size of emerging adults that subsequently must feed more frequently to develop an egg batch. Viral development time inside the mosquito also shortens with higher temperatures, increasing the proportion of mosquitoes that become infectious at a given time. Thus, mosquitoes bite more frequently and are potentially more infectious at warmer temperatures. Marine phytoplankton blooms include red tides that cause diarrheal and paralytic diseases. Vibrio cholera has been found to be associated with marine zooplankton, and blooms from warmer sea surface temperatures could expand this important reservoir from which cholera epidemics may arise.