Just as snowbirds flock to warmer climes when winter settles in, wild creatures seek out weather that suits them. But a changing climate is moving that comfort zone for many animals, including disease-carrying mosquitoes that kill about 1 million people a year.

Stanford biologist Erin Mordecai and her colleagues have made startling forecasts of how climate change will alter where mosquito species are most comfortable and how quickly they spread disease, shifting the burden of disease around the world. A major takeaway: wealthy, developed countries such as the United States are not immune.

“It’s coming for you,” Mordecai said. “If the climate is becoming more optimal for transmission, it’s going to become harder and harder to do mosquito control.”

Mosquitoes and other biting insects transmit many of the most important, devastating and neglected human infectious diseases, including malaria, dengue fever, chikungunya and West Nile virus. Economic development and cooler temperatures have largely kept mosquito-borne diseases out of wealthier Northern Hemisphere countries, but climate change promises to tip the scales in the other direction.

“As the planet warms, we need to be able to predict what populations will be at risk for infectious diseases because prevention is always superior to reaction,” said Desiree LaBeaud, an associate professor of pediatrics in the Stanford Medical School who collaborates on research with Mordecai.

Mordecai’s research has found that warmer temperatures increase transmission of vector-borne disease up to an optimum temperature or “turn-over point,” above which transmission slows. Just as they carry different diseases, different mosquitoes are adapted to a range of temperatures. For example, malaria is most likely to spread at 25 degrees Celsius (78 degrees Fahrenheit) while the risk of Zika is highest at 29 degrees Celsius (84 degrees Fahrenheit).