Research suggests that middle- and high-school students don’t always regard heat exchange as an interaction. (Benchmarks for Science Literacy, p. 84.) To overcome this, you can do this activity with students—either as a “thought” experiment, or a physical exercise requiring you to provide a bucket of ice cubes and a thick mitten.
Ask the students: “Suppose I pass an ice cube to your bare hand. Somebody count the seconds, 1 Mississippi, 2 Mississippi, etc., and then observe changes over time. Think in terms of what is leaving your body, and remember this hint: heat flows naturally to cooler spaces. Can we agree an interaction is occurring? What is it? (Body heat is moving into the ice, melting it.) Let’s try to explain this in terms of heat exchange. Call out phrases that describe the process of ice cube melting/hand cooling, and I’ll write them down on the board so we’ll have a clear statement from our own experience that frames heat exchange as an interaction.”
This teacher sheet is a part of the Green Roof Design lesson.
“Now put the mitten on your hand. I’ll pass you another ice cube. Start the count, and observe change over time. What happens now? What properties can we ascribe to the mitten? Do we agree the mitten limits heat exchange—and therefore acts as insulation? Would you accept a basic definition of insulation as a material that slows the interaction, in the form of movement of air, between two different temperature zones?”