A thin-walled polished aluminum can is filled with hot water and let stand on a magnetic stirrer with a small magnetic bar for stirring the water continuously (so that its temperature is uniform throughout the can). The bottom of the can is insulated with styrophoam. Then a thermometer is inserted from above and the lid is insulated.

Two temperatures were taken as functions of time: temperature of the water inside the can and temperature of the environment.

(Note: The can was polished to suppress the effect of thermal radiation from the surface of the can.)