Superman doesn't really have trouble with fire-type attacks.
http://img409.imageshack.us/my.php?image=837zy.jpg
I did want to reference durability against electrical attacks though, as Superman as often pitted against a certain thunder god...
http://img409.imageshack.us/my.php?image=849px.jpg
Superman can take lightning strikes for fun
http://img409.imageshack.us/my.php?image=855kz.jpg
Even taking on the biggest electrical storm (props to Avalon)
http://img409.imageshack.us/my.php?image=865tq.jpg
Though that was year one Superman (he was much weaker back then), Poseidon's magic/power/storm/lightning knocked Superman out:
http://img409.imageshack.us/my.php?image=878qr.jpg
Acid blasts are no problem.
http://img409.imageshack.us/my.php?image=884tc.jpg
Superman can also take on gas attacks.
http://img409.imageshack.us/my.php?image=890mg.jpg
Superman is also much experienced with handling sonics.
http://img409.imageshack.us/my.php?image=900mi.jpg
Superman takes on a Banshee that knew the Kryptonian language (and thus more devastating).
http://img409.imageshack.us/my.php?image=918dw.jpg
While braced, Superman can casually take energy blasts as back massages.
In this case, he was doing just that till his flight powers went away:
http://img409.imageshack.us/my.php?image=948fs.jpg
Superman has shown the ability to combat energy beams.
http://img409.imageshack.us/my.php?image=956ni.jpg
Superman has taken beams that could level a city, and trust Cyborg, because he's an experienced city leveler. Cyborg also amped himself up later by using the core of the planets power against Superman.
http://img219.imageshack.us/my.php?image=1005ea.jpg
Here's another example of taking on a blast that could've leveled a city, It was fired from Entropy Aegis.
http://img219.imageshack.us/my.php?image=1018ra.jpg
Superman again took on the power of the Entropy Aegis.
http://img219.imageshack.us/my.php?image=1021by.jpg
http://img219.imageshack.us/my.php?image=1031iz.jpg
Superman even took energy attacks from a guy that had the power of all these different alien species, including many energy based one.
http://img219.imageshack.us/my.php?image=1137aq.jpg
Superman can withstand the blasts from Kalibak's Beta club,and even smoosh it.
http://img471.imageshack.us/my.php?image=1165mm.jpg
Darkseid uses an Omega attack fine-tuned to Superman's molecular structure. Superman still takes him on...
http://img471.imageshack.us/my.php?image=1183yv.jpg
Here's Superman surviving another black hole.
http://img245.imageshack.us/img245/1291/1205zz6dt.jpg
Superman also survived the heat of Almerac's core. He's survived Earth's core many times before
http://img471.imageshack.us/my.php?image=1212ms.jpg
Superman was merely knocked out when attacked by Starbreaker's power of a nova.
http://img471.imageshack.us/my.php?image=1224ce.jpg
The guy was powerful to cause the following:
http://img471.imageshack.us/my.php?image=1237pl.jpg
Superman also survived Eradicator's core-of-the-sun blasts.
http://img471.imageshack.us/my.php?image=1242au.jpg
Early in his career, Superman was intially unable to really handle the sun. He did grow in power, but was worried about his durability against the suns extremes
http://img471.imageshack.us/my.php?image=1250ca.jpg
This was soon changed, as Superman survived the Sun (and it was even red at the time, IIRC):
http://img471.imageshack.us/my.php?image=1260jz.jpg
http://img471.imageshack.us/my.php?image=1278cq.jpg
Later still, Superman showed quick revival (even from a depleted state) when entering the Sun:
http://img471.imageshack.us/my.php?image=1286zu.jpg
Superman's withstood all kinds of explosions. Right here he caught a bomb that could've leveled a city block.
http://img471.imageshack.us/my.php?image=1303cd.jpg
In the following scene, he caused an explosion by blasting the gas line. He did so as a diversion to get away from Brainiac:
http://img450.imageshack.us/my.php?image=1342jx.jpg
The explosion of a mother ship.
http://img450.imageshack.us/full.php?image=1369qv.jpg