"Science, Technology and Society" was identified an essential strand in the new Science Education curriculum guide. Shortly after the severe acute respiratory syndrome (SARS) threat to Hong Kong technical dealers introduced Infrared non-contact thermometers as a solution for schools to measure body temperature for a large number of students in a short period of time before they enter the school building for another new daily routine. We found that the devices work erratically beyond our expectation and we worked scientifically and systematically to understand their operation. We then realized that this exploration could be converted into an open-ended learning opportunity for school students to appreciate the connections between scientific and rational deductions, use of technology, critical evaluation of technical products and the appropriate application of technological products to serve the needs of the society.