It sounds like time to bring in the tracking dogs.
It’s faster to wait until night and use a LANTIRN system on an aircraft. Low Altitude Navigation and Targeting Infrared for Night
http://en.wikipedia.org/wiki/LANTIRN
The non-military version can be mounted in a helicopter and likely a drone, and has been used in helicopters for decades. After sundown, people really stick out, even in a tent, because of their IR signature. Even if you hide in a cave, the entrance will likely look warmer. Any fire looks like a volcano.
About the only way to not be seen is to jump in water.