Convection Shmonvection. Apparently being a Jedi makes you immune to being roasted alive over an enormous lake of lava. We'll see more of this as the fight progresses.

The most realistic rule in a roleplaying game for characters interacting with lava is from Dungeons & Dragons 4th Edition. If you touch lava and are not completely immune to fire, you die.

This is realistic.

Of course nobody in this scene actually touches the lava, but even being this close to it should be enough to blister your skin.

Transcript

{Anakin and Obi-Wan fight and move outside on to gantries over the lava}
Anakin: So what if I was jealous?
Anakin: I was abandoned by my mother!
[SFX]: Kzrkzrkk!
[SFX]: Kzrkzrkk!
[SFX]: Whooom!
[SFX]: Whooom!
Anakin: I swore I would never abandon someone the same way.
[SFX]: wmmm...
Anakin: It led me to feelings I'd never felt before.
[SFX]: Whooosh! {lava erupts behind Anakin and Obi-Wan}
[SFX]: Whooom!
[SFX]: wmmm...
Anakin: Nurturing feelings.
{flashback to Anakin and Padmé in the arena on Geonosis}
Anakin: It's my job to protect you, Senator.
{end flashback}
[SFX]: Kzrkzrkk!
[SFX]: Whooosh!
Anakin: I loved and cared for Padmé.
Obi-Wan: Well that ended well, didn't it?