Not everybody is as skilled as you. Hot soup + fish form is enough for me, but I just like using Spirit Form. Really the Spirit Form is just a key. It lets you past those steam vents and yes, it does give you health. Let me explain that in as many words as requested.
Right-click in spirit form to absorb energy-type projectiles that are near you. You must be very close, but be careful because you can still be hurt.
Absorb five projectiles like this and you will regain health.