Thermal Flashlights

A thermal flashlight measures temperature using a non-contact infrared sensor and uses a red-green-blue LED light to turn red for hot and blue for cold. The light “paints” surface temperatures directly onto the materials under examination, making the data easy to understand. With long exposure photography, users can “see” the temperature of their research area.

The open-source design and code for the thermal flashlights were created by Public Laboratory for Open Technology and Science, and modified to fit the context of use; the technology is easily adaptable to how and where users want to map thermal data. We’ve had success bringing the thermal flashlight into university classrooms to involve students in research about the links between electricity, technology, and society. Below are projects, teaching materials, and instructions on how to build and use a thermal flashlight.

Student Projects


Thermal Pollution at Holyrood Electricity Generating Station	Heat Leaks as Urban Public Commons	Thermal Imaging of Fresh Air Intake for Nightingale Hall


Comparison of Window Insulation in Old vs New buildings	Thermal Imaging of Northeastern University buildings	Effective Cooling In Refrigerators


Comparison of Heat Insulation in Two Different Aged Building using a Thermal Flashlight	Inexpensive Thermal Imaging of Decorative Lights in Households	Thermal Flashlight: Tech Failure Spectacle