A thermal imager typically works like a thermometer with a sensor array: it measures how much each pixel heats up and turns that into a picture. But this method has a limit — the device's own noise obscures faint heat. The authors of the new study took a different route: their detector doesn't measure temperature directly but counts rare random events triggered by heat. The hotter the object, the more frequent these events, like raindrops drumming harder on a roof during a downpour.

The device captures infrared light across a broad range — from 3 to 14 micrometers. That's like having a single camera that sees both the warmth of a human body and the blaze of a campfire. Normally, such tasks require two separate detectors, but this one does it alone. The sensitivity is about 80–100 millikelvins, meaning it can spot a temperature change of less than a tenth of a degree. For comparison, your skin warms by a few tenths of a degree when you press your palm against a cool wall.

This approach could find use in night-vision cameras, security systems, and medical diagnostics — anywhere you need to see heat without bulky cooling.