Players can experience weird whispers, get attacked by phantom mutants, and start losing health while exploring the world of Stalker 2: Heart of Chornobyl. These are the effects of PSI-radiation affecting Skif, damaging his mental state, and slowly plunging him into madness. Although you can choose to use PSI-Block consumables to keep a level head, wearing an armor or suit that offers high PSI protection is a far better solution.