Warmer temperatures and the year-long drought in California could have more immediate dangerous results, including an increase in West Nile virus cases. West Nile virus is an infectious disease where infected mosquitoes spread the virus.

According to public health officials, there were more than 800 cases of the disease reported in 2014. Out of them, about 31 patients died. It was the highest West Nile death for any state in the country last year. The more serious form of the virus can cause neurological damage and can result in encephalitis or meningitis.

As per experts, just 1% people affected with the virus become seriously ill, but older people, who are with pre-existing medical conditions like high blood pressure and diabetes, could be at greater risk of developing serious illness due to the virus. The ongoing drought in California could spread the virus by limiting water sources disease-carrying mosquitoes, as per the Associated Press.

Karen Smith, director and state health officer of the California Department of Public Health, said, "As birds and mosquitoes sought water, they came into closer contact and amplified the virus, particularly in urban areas. The lack of water could have caused some sources of water to stagnate, making the water sources more attractive for mosquitoes to lay eggs".

In addition, warmer temperatures could also contribute to the spread of the disease. The season of West Nile virus usually begins in summer, where high temperatures help in spreading the disease. The virus peaks in mid-July through September. According to reports, this year, the hot weather has encouraged the spread of the deadly virus to start early. Earlier, a West Nile virus-positive mosquito was recorded in the San Fernando Valley, which means that the mosquito with the virus is present many months ahead of schedule.

Symptoms of the deadly virus usually include high fever, stiff neck, a severe headache, and confusion.