The authors developed a demonstration with two similar setups that provide students with both the prior experience to form an expectation and the discrepancy to grab their attention. They follow the demonstration with a structured exploration format that gives students a method for experimenting to find the one built-in difference (i.e., the variable) that caused the different results between the two setups. Because the demonstration-experiment approach can be applied to various science content areas, inquiry is not the focus of just a single unit, but is used to teach content throughout the school year. This article describes one such activity that deals with the concepts of density and convection currents and is called "Chill Out." (Contains 6 figures.)