The authorities in Chile have raised the alert level for the Villarrica volcano to orange, the second-highest, after they registered a gradual increase in its activity.
Villarrica is one of the most active volcanoes in South America.
The 2,847m-high (9,340ft) volcano last erupted in 2015.
Some 30 families who live in a radius of 8km (5 miles) from the crater will be evacuated and access to the area will be blocked, officials said.
Schools in the nearby towns of Pucón and Villarrica will close for five days from Monday and pupils will be taught online.
The stratovolcano, which is located 750km south of the capital, has been active for about 650,000 years. There have been close to 50 eruptions since the 16th Century.
The cone-shaped snow-capped volcano is popular with climbers and skiers.
A national park on its slopes has been closed while the orange alert is in place.