The HEAT stat determines the amount and types of City Guards trying to arrest you. As HEAT levels rise, soldiers, bounty hunters, and other NPCs will also try to arrest/capture you. At this point, they will begin to move on from arresting to killing you.
After 1 month (if under 20 HEAT) or 6 month (over 20 HEAT) in game you will loose 10 HEAT points, completing city quest also reduce your HEAT.
Committing crimes increases your HEAT.
Insulting townsfolk: +1 HEAT, Fighting townsfolk: +2 HEAT, Killing townsfolk +3 HEAT.
Insulting criminals: +1 HEAT, Fighting criminals: 1 HEAT, Killing criminals +1 HEAT.
Insulting city guards: +2 HEAT, Fighting city guards: +3 HEAT, Killing city guards: +5 HEAT.
Insulting children, old people or companions: +3 HEAT, Fighting children, old people or companions: +5 HEAT.
Attacking Military personnel: +20 HEAT.
Attacking Government Personnel: +70 HEAT
Committing a temporal crime: +90 HEAT
Damaging federal property: +50 HEAT
Killing a member of an endangered species that is under protection: +60 HEAT
Attacking a non-hostile higher being: +90 HEAT
10-20 Heat: Townsfolk will call the city guards and sometimes attack you.
20-30 Heat: 1 or 2 city guard vehicles will be sent after you. City guards will now be more aggressive.
30-40 Heat: 3 or 4 city guard vehicles will be sent after you. City guards will now try to kill you more instead of arresting you.
40-50 Heat: 6-10 city guard vehicles get dispatched. 2 road blocks will be placed around you. City guards will now rarely arrest you. They are very interested in killing you.
50-70 Heat:15-20 city guard vehicles get dispatched. 4-6 road blocks will be placed around you.
70-90 HEAT: This is a problem for the military now. 10-20 soldiers will attack you.
90-99 HEAT: 30-50 soldiers will attack you and are allowed to use heavy weapons against you. The entire Zone is now aware of your crimes. No shopkeeper will sell you items until you lose the HEAT. Bounty hunters are now dispatched after you.
100 HEAT: You won't survive a minute. Even townsfolk will try to kill you. You are the planet's number 1 enemy. It's almost impossible to escape now, and every faction will try to kill you too.
Federal Offenses: Government agents hunt down the player.
Temporal Crimes: Time Police Officers hunt down the player.
Faction-specific Crime: Enforcers exclusive to the offended Faction hunt down the player.