Besides creating HII regions, newborn hot stars impact their hosting clouds in other ways. Their powerful winds exacerbate the cavitation of these clouds while adding further energy in the form of shock waves. At the end of their lives, the massive stars explode as supernovae that shock the ambient gas to million-degree temperatures. Consequences of this energetic activity include starburst outflows and, ultimately, wholesale reconfigurations of the ambient interstellar medium.