We do think the copter may have basic heat sensors.
With only her head showing she'd look like a rock-rabbit to any heat sensors.
At present, the Hunters would almost certainly be tracking them by infrared heat sensors.
Perhaps the guy has a heat sensor where his tonsure should be.
The Hunters have been using heat sensors to track us.
If the Hunters came up quickly, their heat sensors would tell them where she had been.
The ship would certainly carry a heat sensor, but not a portable one.
Not perfect, of course; a heat sensor would pick him out in a flash.
Would've thrown off the heat sensors, and probably the search dogs.
As a result, it can be used as a heat sensor.