There are glitches and bugs with the heat after playing the game for a long period of time or after completing some sort of missions. This was tested on Xbox One and PC. I had found three glitches, but there might be more.
After the mission Aeropuerto Scramble, I lost the heat. However, 4 Black Hand vehicle (3 Warrior Offroader, 1 Próspero Hunter Bike) and a helicopter (Spectre Attack Heli) were following me everywhere I go. They spawned behind me. When I engaged on them, it was always the same vehicle spawning after me. I couldn’t have freedom at the airport because of this issue bappening. When I flew a fighter jet and got heat, there were no fighter jet. I fixed it by going to a frontline zone. This was on Xbox One. It didn’t happen on PC.
After a long period of time playing, there were no vehicle spawning after me during heat. It was pretty easy to lose the heat. Restarting the game fix it. This was both Xbox One and PC.
After some mission, I was stuck at low heat. It was always buggy and motorcycle going after. I retaliated as much as I can, but still it was the same vehicles. There were no helicopters, tanks, fighter jet and armoured vehicles. Restarting the game fix it. This was Xbox One. It didn’t happen on PC.