Thermal-imaging cameras were originally developed for the battlefield. Aerial-drone operators and snipers track targets using infrared radiation, which can distinguish between ambient temperatures and heat generated by the human body. They are also used increasingly for domestic surveillance—deployed on mobile police watchtowers and on law enforcement helicopters and drones.

In 2014, a low-resolution thermal-imaging camera was introduced for sale as a clip-on accessory for smartphones, part of a growing commercial market for infrared technology. I was curious to see how this technology designed for surveillance renders the human form, and thereby better understand how citizens appear when viewed by government security forces. I began photographing areas of heightened security around the United States, including New York City, Washington, and anti-government protests.