If the target also has HP Leak, Poison, Regen, or Sap, that may not happen, as Heat treats healing or damage from these effects as a turn and kills the victim. Air Anchor is the only item or ability in the game that can inflict Heat. This status can be prevented by being immune to Death, but the self-destruction will trigger even if the victim gains immunity to Death spontaneously before their next action.
Heat status causes the target to become KO'd if any action is attempted. Quina's Blue Magic Mustard Bomb will cause Heat status. Soulcage, Valia Pira, Drakan, and Maliris will use the Mustard Bomb magic, and Tiamat can use a Jet Fire attack that also causes Heat.
Pyretic is a recurring status that causes those afflicted to take damage each time they perform an action, including movement, and can lead to self KO if players don't wait until effect wears off.
The Machinist job contains several actions that fill a resource known as the Heat Gauge, which the Machinist will use to unleash even more powerful attacks. While normally represented on their job gauge, it is also represented by the Heat status in PvP content.
Overheated inflicts damage over time with intense heat. It is distinct from the Burnt status, which can occur from Fire damage and deals continuous Fire-elemental damage.