 Transmission occurs when someone is bitten by an infected mosquito. Experts say with higher temperatures and higher rainfall amounts, mosquitoes that carry dengue viruses are extending their range. Common symptoms are fever, nausea, vomiting, and a rash. They begin within two weeks and last two to seven days. Meanwhile, pest control companies are on overdrive with calls up 30% in some areas due to bugs and rodents trying to beat the heat.