It’s pitch black along a river. My phone screen flutters then bursts red, shapes emerging from the dark. 
I’m testing a tiny thermal-imaging camera on a night hike. Campers huddle around a fire a few hundred feet ahead. On my screen I can see them through the night.
The Seek Thermal XR is smaller than my thumb. But its tiny lens senses infrared radiation via a microbolometer so sensitive it can detect body heat a quarter-mile away.
Night Vision

