Why have mosquitoes invaded cold regions of Himachal Pradesh?

A study has found that the mosquitoes have invaded cold Himalayan regions of Himachal Pradesh due to an increase in temperature and relative humidity in the last decade. Mosquitoes have begun breeding in spring-fed pools, shaded streams, humid corners inside houses and cattle sheds. They are also breeding in any other warm places they can find across the lower-lying Himalayas.