Understanding thermal concepts constitutes one of the most important challenges in teaching science as these concepts are central to the principals of science and allow students to build connections among scientific disciplines. From an early age, students' interaction with daily phenomena and real situations comes to shape their conceptions of thermal concepts, which continues to guide them throughout their education. Conceptions that are sometimes different from the scientific norm. This article presents six qualitative experiments/demonstrations using a low-cost, easy to make apparatus that introduces students to thermal concepts such as heat conduction in solid bodies and thermal expansion. These are appropriate for high school or college students enrolled in non-major science courses (e.g., departments of primary education) and can easily be performed by elementary or middle school students, but care must be taken when dealing with tealight candle flames.