Figure 4. Warm water in differently coloured cups (left side) and water of different temperatures in identical cups (right side)

From

Can You See the Heat? – Using a Thermal Imaging Camera in the Chemistry Classroom

Claudia Bohrmann-Linde, Simon Kleefeld

World Journal of Chemical Education. 2019, 7(2), 179-184 doi:10.12691/wjce-7-2-18