A quick dbjm done at the point where you would space jump out of the lava with the gravity suit will easily get you out of the lava. The part you want to go to is by the wall at the other end of the lava pool. Don't actually go right up to it before doing the dbjm; leave yourself a little room. The wall only needs to be close enough that Samus will land safely on the ground above the lava when you morph out.

So, this method probably sounds good and all, but you're also probably wondering if there's a way to not take that much damage from the lava before actually reaching the dbjm point. Fortunately there is, to the point where crossing the room with it in an NTSC hard 24% game is perfectly doable (PAL has to be confirmed).

Before going in the lava, take a look at the left wall. You can reach an invisible ledge if you land high enough against the wall. The spot you want to land is where Samus is aiming with R in this picture, although you can actually land a bit lower and walk up against the wall to reach the highest point.

Space jump to the ledge and walk up against the wall until Samus won't go any higher, then turn around. Make sure your view of the room is similar to this picture before the next step.

At this point, space jump to the end of the lava and morph while still in the air. As soon as you hit the bottom of the lava, do a dbjm and Samus should leap out perfectly if your positioning was good.