The audio indicator heartbeat sensor thing on the left in thermal vision isn’t just cosmetic and DOES actually unreliably work and points you in the general direction of FT members regardless of whether or not they’re mudded.
You rotate the camera and wait until the indicator lights up, looks as wide as it’s capable of getting and follow it and it’ll take you within vicinity of the fireteam. Wider = warmer, thinner/dimmer = colder.
Why these things aren’t explained ingame, I don’t know. Neither was scanning/tagging players.
You can keep track of FT members with this without use of target isolation (Deadeyebuddha would be proud) and it works really well with Observant.
Not sure if accuracy increases with less FT members.
AMA