Heat

The Kindred wear the Masqurade like a second skin while telling lies almost on reflex. They move unseen beneath the surface of the mundane world, the city of mortals. However their passing makes ripples both small and large, and sometimes the city notices.

The Kindred retracts his fangs allowing the beggar to stagger off smiling, as the ex-city watch guard peers out from his second story window in surprise.

The alley rat stays very still watching the creature in blind rage with claws and fangs as the puddle forms at his feet.

The Priests want to know what happened to one of the own.

The City Watch has noticed an uptick in recent deaths beyond the Warrens.

Hunters may come after the Kindred, his followers, herd or haven. Priests may set out on a quest to investigate or rid the world of darkness. Blind luck may give the guards a tip of a creature pretending to be mortal. Higher Haven ratings and other unique edges and powers may dampen this or act as a layer of protection.

Heat is a secret rating maintained by the Storyteller. Being both dead and alive may generate Heat. Having a low Humanity may generate heat.
Things like supernatural power or abilities granting Scale really pushes Heat up. Botches may also be used to increase Heat. Certain things may reduce the Heat. As Heat builds it can ignite into fire, and fire can burn leaving the Heat diminished.
This mechanic is deliberately presented to players very vague as it is a meta-game mechanic that will have narrative and story impact. The mechanic is not meant to be analyzed or discussed in-game by characters.

Inspiration & Reference

Heat from Blades in the Dark

Collateral Damage from Aberrant

The Churn from The Expanse

Heat from Shadowrun 6th World