How do imolation and adaptation interact?

[Firepotato32 35]

Is it worth running adaptation on my ember? Or is the dr from imolation enough in most cases

[taiiat 28,274]

in the current state of things, all forms of DR are functionally the same, as unless you use Aviator/Aerodynamic or Elemental Resist Mods with Adaptation, then it is all functionally Multiplicative.

and what level of EHP is enough for you depends on how much Damage you normally take.

[ShichiseitenYasha 697]

They stack multiplicatively. The interaction would be that one of them reduces damage say 50%, then the next would reduce the remaining damage (so, the 50% you're taking) by say 80%. If you were taking 100 damage in this case, it would be reduced by one half to 50, and then that 50 would be reduced by four fifths, to 10. 

Whether or not you run adaptation on top of immolation depends on the content you do, and the enemies you face. If you're facing level 30-40 Grineer, you can just shrug off damage in general due to shield gating. If you're facing level 120 infested, well you might want to run adaptation or Antitoxin(these are additive, by the way. So, if you reach 55% toxin resistance through adaptation while you have Antitoxin equipped you won't take toxin damage at all while you are touching the ground) as even 75% of their damage could be more than your health bar and armor can account for.