The mountain never "cooled off" but has been in what is described as a constant state of eruption since the big one. A "constant state of eruption" can sometimes mean no more than that the dome in the middle of the crater is growing (lifting) in small but measurable ways. Other times it is more violent and dramatic, e.g. steam jets, ash plumes, rock slides and the like. A new word -- lahar -- has entered the vocabulary of folks around here. I think it comes from Indonesia. It means flows of mud and debris which can sluice down the side of a volcano. It happens in places where it rains a lot .. like here! The kids who go to school in the shadow of the mountain now have to learn lahar evacuation routes and procedures, much as we learned how to hide under our desks in the event of an atom bomb attack when I was in elementary school.