The Middlesex County town of Sudbury will spray for mosquitoes Monday and Tuesday after a 5-year-old girl tested positive for Eastern equine encephalitis.
Town officials say she is in critical condition.
This week's spraying will start at dusk and last until 11:30 p.m.
Brian Farless, superintendent of the East Middlesex Mosquito Control Project, advises residents to close their windows and stay indoors for half an hour after the truck goes by their house.
"If you're outside, just try to go inside. It's always good to avoid pesticide exposure," he says, but he adds that people tend not to be affected by this type of spraying.
Mosquito control efforts have also taken place in several other high-risk Massachusetts communities over the past few weeks.
So far this year, there have been seven confirmed human cases of EEE in the state.
One of the victims, a Fairhaven woman, died of the mosquito-borne virus.
Officials in Rhode Island will also spray for mosquitoes this week.
They plan to spray Sunday night in Central Falls, Westerly, West Warwick and parts of northern Rhode Island near the Massachusetts towns of Uxbridge, Douglas and Mendon.