High temperatures associated with the El Niño phenomenon are generating conditions that favor the appearance of dengue and gastrointestinal diseases in nine regions of Colombia. ^[1] Symptoms requiring immediate medical attention include difficulty breathing, severe dehydration with dry mouth, persistent vomiting, gum or nose bleeding, unexplained bruising, excessive drowsiness, and convulsions. ^[2] The El Niño phenomenon, which has not yet reached full intensity, is accelerating reproduction of the Aedes aegypti mosquito in nine regions of Colombia, with a visible increase in dengue and gastrointestinal disease cases. ^[3] Carmen Hernández, the national director of Integrated Risk Management in Health at Bienestar IPS, explained that elevated temperatures allow the Aedes aegypti mosquito to complete its life cycle faster. ^[4] Signs of alarm requiring immediate attention to an emergency service include difficulty breathing, severe dehydration, persistent vomiting, bleeding from gums or nose, and body temperature exceeding 40 degrees Celsius. ^[5] Experts warn that during periods of drought, families storing water in tanks, buckets, and pools may inadvertently create mosquito breeding sites if containers remain uncovered or are not cleaned regularly. ^[6] Both specialists agree that during droughts, families store water in tanks, swimming pools, buckets, or containers, and when these are uncovered or not periodically cleaned, they become ideal breeding grounds for the dengue-transmitting mosquito. ^[7] Carmen Hernandez, national director of Comprehensive Health Risk Management at Bienestar IPS, said that high temperatures speed up the Aedes aegypti mosquito's life cycle and accelerate replication of the dengue virus inside it, increasing its ability to transmit the disease. ^[8] Emiro Buendia, a physician at Serena del Mar Hospital in Cartagena, Colombia, said that El Niño increases temperatures and decreases rainfall, and that the Aedes aegypti life cycle shortens from 12 days at 30°C to 7 days at 32-35°C, making mosquitoes smaller, hungrier, and more likely to bite. ^[9]