Presumably it's measuring heat or something vaguely relevant but I don't trust my immediate visceral reaction to it.
Several instruments can sense emissions in short-wave IR which light up for fires (and hot smoke plumes, and some industrial plants). E.g., VIIRS which is a successor to MODIS (https://www.earthdata.nasa.gov/data/instruments/viirs/viirs-...).
The resolution in the posted image is much better than satellite, however. This implies that it's an airborne platform like FIRIS (https://wifire.ucsd.edu/firis-in-depth). It also uses IR.
Presumably it's measuring heat or something vaguely relevant but I don't trust my immediate visceral reaction to it.