Though the "normal" small eruptions of lava are not dangerous, you should be aware of the possible danger. The local authorities are very aware of Stromboli's state, you should listen to them. If paths to the craters are closed, don't go there. Never climb up the volcano without a local guide. Don't leave paths. Tours up the Stromboli aren't easy walks. You should be well-equipped, healthy and in good physical condition when going there.As Stromboli is small and its environment is sensitive, you should treat it carefully. Bring a flashlight (torchlight) along with you, as the streets are not illuminated. http://wikitravel.org/en/Stromboli