What are the different forms of nibbāna? Often people refer to nibbāna with the cessation of all mental defilements.
However, does nibbāna also encompass 'momentary cooling off', for example when one engages in the various contemplations / mindfulness of breathing? If I, for example read suttas, I feel my mind is getting calmer and calmer, as if a heavy burden wanes.

Another 'momentary nibbāna' would probably be samādhi, where all hindrances lie dormant, right?
This talk may help answer the question: Nibbāna for Everyone.