In Just Cause 2 there is a heat bar. I want to know how high can your heat get? The highest level of heat I've experienced is level 3. What happens at that heat, and how can it be possible?
As mentioned on the Just Cause Wikia page discussing Heat, Just Cause 2 has five levels of heat but at the start of the game you're only able to get as high as the second level of heat. You unlock additional levels for every 100,000 Chaos points you earn (100,000 for level 3, 200,000 for level 4, 300,000 for level 5).
Everytime you gain an additional level of heat, more military forces will be dispatched to deal with you. At heat level 3 helicopters will also be dispatched and as your heat increases further certain units will be replaced with more upgraded versions (the example given on the Just Cause Wikia is Wilforce Jeeps at lower heat being replaced with Chepachet PVDs at heat level 5).