Would your students like to take care of a penguin? To be a “penguinsitter,” they would have to know what conditions that bird needs to survive. One important factor would be temperature. In this activity, you will challenge student groups to prove that they could care for a penguin by demonstrating they can maintain the temperature of a glass of water at 10°C (using ice and/or body heat from their hands) for 15 minutes, recording the temperature for every 30 seconds, and graphing their data. By reflecting on the procedure, students will learn about the dynamics of a closed system, the nature of water, and the value of adjusting to fluctuating environmental conditions.