How to lower the "heat" level in Just Cause 2?

Solution 1:

1. Use a mod (for example Less Psychic Police or Less Vehicle Heat) to increase the threshold of police reaction
2. Run/fly away. Police are only aware of you within a certain range, so if you call in either an extraction (can't with heat, forgot about that), or a black market chopper and fly up really high, the heat will fade. Then just bail out/reingress and continue the fun.

Solution 2:

You basically need to kill all the military and then get the hell out of there, or just get the hell out of there. If you have a fast vehicle (fully upgraded chopper or jet is best), then you can take to the sky with relative ease.

Barring that, you can get some decent speed with the grapple/parachute combination through the forests and up the mountains. And hijack a chopper if need be.

Solution 3:

If you are near an ocean or a body of water, go into the water. The military is stupid so they wont notice you. not too shallow though because then you will stand up.

Solution 4:

If you play on easy, your heat will not rise as quickly, and will return to normal faster. When your heat gets high, move to a different area controlled by a different faction. I found this makes it very easy to keep heat below level 3.