Inquiry-based activities, where students engage in guided discovery of concepts, have been demonstrated to be highly effective in repairing student misconceptions. For these activities to have the proper effect, students must make predictions, observe how the “real world” confirms or refutes those predictions, and then have the opportunity to restate their ideas based upon their observations, thereby correcting any misconceptions. For some key concepts in thermodynamics and heat transfer, it is difficult to create a physically realizable activity for undergraduates. Therefore we have turned to Flash-based simulations to bring the activities to life. We will demonstrate several web-accessible activities meant to clarify concepts of entropy, reversibility, temperature, and the differences between factors impacting the rate and amount of heat transfer. Students perform significantly better on concept inventory tests after using these simulations.