A space marine with TB 10 will take damage from it because it will Zealous Hatred on a 10 (meaning he'll die in about 3 minutes).

And before that he'll go unconscious due to Fatigue.

Ignore post.

Not that a Space Marine in PA should even take dmg from being on Fire. PAs are basically flame retardent and without actual fuel the fire would go out or not catch at all. Unless its a really really hot fire, like Heldrake spit

Even in PA, if you're sprayed with Promethium , that burns hotter than now a days napalm, I think you get hot in that tin can of yours.

"Burn baby burn, Disco Inferno"

PS. Salamander would propably feel like home.

Promethium being fuel...

Promethium being fuel...

And is what's burning. It's not the armour itself that's burning, and causing damage.

Promethium is supergasoline. It's sticky.

I remember hearing some where that the Imperial Guards primary way of killing Traitor Astartes was massive amounts of Las fire until the Astartes cooked in thier armor. If lasguns can do that fire should still be a threat.

That's usually how I describe lasguns injuring people through power armour. I don't think they literally punch holes in it.