We suggest students work in pairs and share water bottles in table groups of four. Homeschool students will need a partner for this activity.

You will need access to hot water for this activity. You can fill bottles an hour or two ahead of class if you have a cooler (or a cardboard box and a bath towel) to keep the water bottles hot.

Prep Aluminum Foil

Tear aluminum foil into 10” squares. Each pair of students (or each homeschool student) needs two 10” squares.

Fill the Plastic Bottles

Each group of four students (or homeschool student) needs two plastic bottles. Half of the bottles will be filled with cool or cold water and the other half will be filled with warm or hot water. The difference in temperature between the two bottles has to be enough to feel easily with bare hands. You can use ice water and warm water or you can use very hot water and cool water. You just need to make sure there is a definite difference.

You can keep your hot bottles hot (or your cold bottles cold) for a couple of hours if you put them in a cooler or in a cardboard box with bath towels as insulation.