lazarus pit it is
Doubt it, dont think they will use it this soon. I'm guessing Malcom Merlyn will nurse him back to health in some unconventional powerful way (he has a green vial for necklace in one of the scenes, speculated to be from fountain of youth/lazaruz pit). In the promo for next ep, Ollie was found just on the edge of the mountain by someone who is walking towards him. Unless they carry him to the pit, I doubt it will be uses.
Apparently speculated that the coming 2-3 eps will focus on the other peeps of his gang while Ollie is awol from the screen.